Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
  • B63H—MARINE PROPULSION OR STEERING
  • B63H9/00—Marine propulsion provided directly by wind power
  • B63H9/04—Marine propulsion provided directly by wind power using sails or like wind-catching surfaces
  • B63H9/06—Types of sail; Constructional features of sails; Arrangements thereof on vessels
  • B63H9/067—Sails characterised by their construction or manufacturing process
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
  • B63H—MARINE PROPULSION OR STEERING
  • B63H9/00—Marine propulsion provided directly by wind power
  • B63H9/04—Marine propulsion provided directly by wind power using sails or like wind-catching surfaces
  • B63H9/06—Types of sail; Constructional features of sails; Arrangements thereof on vessels
  • B63H9/067—Sails characterised by their construction or manufacturing process
  • B63H9/0671—Moulded sails
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
  • B63H—MARINE PROPULSION OR STEERING
  • B63H9/00—Marine propulsion provided directly by wind power
  • B63H9/04—Marine propulsion provided directly by wind power using sails or like wind-catching surfaces
  • B63H9/06—Types of sail; Constructional features of sails; Arrangements thereof on vessels
  • B63H9/067—Sails characterised by their construction or manufacturing process
  • B63H9/0678—Laminated sails

Definitions

• the present invention is directed to the field of sails and methods for their manufacture.
• Sails can be flat, two-dimensional sails or three-dimensional sails. Most typically, three-dimensional sails are made by broadseaming a number of panels. The panels, each being a finished sector of sailcloth, are cut along a curve and assembled to other panels to create the three-dimensional aspect for the sail. The panels typically have a quadrilateral or triangular shape with a maximum width being limited traditionally by the width of the roll of finished sailcloth from which they are being cut. Typically the widths of the sailcloth rolls range between about 91.5 and 137 centimeters (36 and 58 inches). Sailmakers have many restraints and conditions placed on them.
• a goal of modem sailmaking is to create a lightweight, flexible, three-dimensional air foil that will maintain its desired aerodynamic shape through a chosen wind range.
• a key factor in achieving this goal is stretch control of the airfoil. Stretch is to be avoided for two main reasons. First, it distorts the sail shape as the wind increases, making the sail deeper and moving the draft aft. This creates undesired drag as well as excessive heeling of the boat. Second, sail stretch wastes precious wind energy that should be transferred to the sailcraft through its rigging.
• the first way sailmakers attempted to control sail stretch is by using low- stretch high modulus yams in the making of the sailcloth.
• the specific tensile modulus in gr/denier is about 30 for cotton yams (used in the 1940's), about 100 for Dacron® polyester yams from DuPont(used in the 1950's to 1970's), about 900 for Kevlar® para- aramid yams from DuPont (used in 1980's) and about 3000 for carbon yams (used in 1990's).
• a still further approach has been to manufacture simultaneously the sailcloth and the sail in one sector on a convex mold using uninterrupted load-bearing 15 yams laminated between two films, the yams following the anticipated load hnes. See U.S. Patent No. 5,097,784 to Baudet. While providing very light and low-stretch sails, this method has its own technical and economic drawbacks. The uninterrupted nature of every yam makes it difficult to optimize yam densities, especially at the sail comers. Also, the specialized nature of the equipment needed for each individual sail makes this a 20 somewhat capital-intensive and thus expensive way to manufacture sails.
• the third basic way sailmakers have controlled stretch and maintained proper sail shape has been to reduce the crimp or geometrical stretch of the yam used in the sailcloths.
• Crimp is usually considered to be due to a serpentine path taken by a yam in the sailcloth. In a weave, for instance, the fill and warp yams are going up and down >5 around each other. This prevents them from being straight and thus from initially fully resisting stretching.
• the yams tend to straighten before they can begin resist stretching based on their tensile strength and resistance to elongation. Crimp therefore delays and reduces the stretch resistance of the yams at the time of the loading of the sailcloth.
• Crimp is not limited to woven sailcloth and can occur with laid- up constructions also.
• Crimp in sailcloth made of laid-up yam can be created in several 5 different ways.
• lateral shrinkage of the films during many conventional lamination processes induces crimp into the yams.
• significant crimp of these yams is induced during lamination of the sailcloth between high-pressure heated rolls. This is because the heated film shrinks laterally as it 10 undergoes thermoforming, typically about 2.5% with this lamination method. The result is catastrophic with regard to the stretch performance for the composite fabric in highly loaded applications.
• the yams used are typically multifiber yams. Twist is generally added so .5 that the fibers work together and resist stretch along the curved trajectories. If no twist were added, only a few fibers would be submitted to the loads, that is the ones on the outside of the curve. This would substantially limit the ability of the sail to resist stretch. While the tiny yam spirals created using the twisted multi-fiber yams help increase load sharing amongst the fibers and therefore reduce stretch, there is still crimp induced as the 0 spiraled yarns straighten under the loads. The twist in the yams is therefore a necessary compromise for this design, preventing however this type of sailcloth from obtaining the maximum possible modulus from the yams used.
• the sailcloth shown in Meldner's patent may, in theory, reduce crimp problems. However, it is designed to be used in Tri-radial construction, which results in its own set of problems. Meldner laminates between two films continuous layers of diameters five times less than conventional yams. The continuous unidirectional layers are crossing-over each other to increase filament-over-filament cross-over density, which is believed to minimize crimp problems and increase shear strength. Meldner is limited to the use of very small high performance yams, which are expensive. The cost of those yams affects greatly the economics of this approach and limits it to "Grand Prix" racing applications. In addition, this design of sailcloth is not intended to offer constant strain qualities; rather stretch and strength resistance are designed to be the same throughout the entire roll length of the sailcloth. Only a small number of the continuous unidirectional filaments end up aligned with the loads.
• U.S. Patent Application No. 09/173,917 filed October 16, 1998 and entitled Composite Products, Methods and Apparatus describes a low stretch, flexible composite particularly useful for making high performance sails.
• the composite includes first and second polymer films with discontinuous, stretch resistant segments therebetween.
• the segments extend generally along the expected load lines for the sail.
• the segments have lengths which are substantially shorter than the corresponding lengths of the load lines within each sail section.
• the sail can be either two-dimensional or three dimensional.
• the two-dimensional sails can be made from one section or a number of flat sections seamed together.
• Three dimensional sails can be made using one or more molded sections of the composite sheet or several flat sections can be broad seamed together to create the three dimensional sail.
• the sail can be designed to exhibit generally constant strain qualities under a desired use condition and to permit low stretch performance to be optimized by minimizing the crimp, that is the geometrical stretch, of the yarns.
• the present invention is directed to a sail body and a method for making a sail body which is particularly useful for making relatively large sails using a reduced number of sail sections.
• a large multiple section sail for an 80 foot boat will use 35 to 40 sections for a conventional cross cut sail and about 120 panels pre-assembled into 5 or 6 large sections for a conventional tri-radial sail.
• that same sail made according to the invention can be made from 5 or 6 sail sections thus reducing the cost for the sail.
• a finished sail includes a number of sail sections joined along their edges.
• Each sail section includes a reinforced material laminated between first and second films.
• the reinforced material includes sectors of reinforced material, each sector having a set of generally parallel reinforcement elements, such as fibers.
• the sectors are arranged in an overlapping pattern and so that the set of reinforcement elements are generally aligned with the expected load lines for that section of the sail body.
• the sectors of reinforced material are preferably elongate sectors in which at least the majority of the sectors have lengths at least three times as long their widths. Sections can be made of different shapes but are typically triangular or quadrilateral.
• the reinforced material is typically a mesh or scrim containing sets of parallel, transversely oriented fibers. The mesh or scrim can be either woven or unwoven.
• a sail body is made from a plurality of sail sections by arranging elongate sectors of reinforced material on a first film in an overlapping pattern, each sector having a set of generally parallel reinforcement elements, such as fibers.
• the sectors of reinforced material are preferably elongate sectors in which at least the majority of the sectors have lengths which are at least three times as long as their widths.
• the arranged sectors of reinforced material are laminated between first and second films to form a sail section.
• the sectors are preferably arranged so that the set of generally parallel reinforcement elements are generally aligned with the expected load lines for that sail section of the sail body.
• the reinforced material is preferably a prepreg material, that is a material that is impregnated with an uncured adhesive.
• the arranging step may be carried out using, for example, triangular or quadrilateral sectors of the material.
• the sail sections are typically joined by broad seaming the sail sections to one another along their adjacent edges.
• Fig. 1 is a plan view of a sail made according to the present invention with an exemplary set of expected load lines shown in dashed lines;
• Fig. 2 schematically illustrates cutting sectors of reinforced material from a roll of reinforced material
• Fig 3 illustrates arranging a single layer of tnangular sectors of reinforced mate ⁇ al on a film
• Fig. 4 illustrates arranging two layers of t ⁇ angular sectors of remforced matenal on a film
• Fig 5 illustrates arranging quadnlateral sectors of reinforced matenal on a film
• Fig. 6 illustrates capturing sectors of reinforced mate ⁇ al between two films to create an uncut sail section
• Fig. 7 suggests how a set of sail sections can be joined to create a sail body
• Fig. 8 is a simplified end view illustrating placement of the mate ⁇ al stack of Fig 6 between two high- friction, flexible pressure sheets stretched berween frames, the frames earned by upper and lower enclosure members, with a three-dimensional mold element used to create a molded sail body, Fig. 8 A shows the structure of Fig.
• Fig 1 illustrates a sail 2 made according to the invention
• sail 2 includes a sail body 3 and has three edges, luff 4, leech 6 and foot 8 Sail 2 also has three corners, head 10 at the top, tack 12 at the lower forward corner of the sail at the intersection of luff 4 and foot 8, and clew 14 a the lower aft corner of the sail at the intersection of the leech and the foot
• sail 2 is typically a molded, generally t ⁇ angular, three-dimensional sail, it could also be a two-dimensional sail and could have any of a va ⁇ ety of shapes
• the finished sail 2 includes gussets 16 at head 10, tack 12 and clew 14 and selvage 18 along luff 4, leech 6 and foot 8 to create the fimsned sail A process suitable for making sail body 3 and its construction will now be discussed Fig.
• Mate ⁇ al 20 illustrates a roll of adhesive-impregnated, uncured remforced mate ⁇ al 20. also called a prepreg or a prepreg mate ⁇ al.
• Mate ⁇ al 20 is typically made of an uncured adhesive such as a copolyester resin, and a mesh or sc ⁇ m 22 of fibers or other reinforcement elements.
• the mesh or sc ⁇ m 22 will typically be unwoven but may be woven for increased tear resistance.
• Mesh or sc ⁇ m 22 preferably includes a set of first reinforcement elements 24 which run parallel to one another along the length of material 20 and a set of second, generally parallel reinforcement elements 26 which are arranged transversely to. typically perpendicular to, reinforcement elements 28.
• Reinforcement elements 24, 26 can be made from a variety of materials such as monofilament material, multifiber yams made of, for example, carbon fiber, aramid fiber, polyester fiber or fiber sold under the trademarks PBO®, Pentex® or Spectra®. Reinforcement elements may be, for example, cylind ⁇ cal or flattened in cross-section and may be made of twisted or untwisted fibers. Reinforcement elements 24 are typically, but need not be, the fibers used to be generally aligned with the expected load lines 28 of sail 2. In one embodiment, first and second reinforcement elements 24, 26 are made of 500 denier untwisted multifiber yams and twisted multifiber yams, respectively. Second reinforcement elements 26 are preferably twisted multifiber yams for increased tear resistance.
• first reinforcement elements 24 is, in one embodiment, about 3mm and the spacing between second reinforcements elements is about 10mm.
• first and second reinforcement elements 24, 26 could be made of different mate ⁇ als and could be made with the same or different diameters. Also, the reinforcement elements could have equal or unequal lateral spacing as well.
• the choice of reinforcement elements 24, 26, their o ⁇ entation and their spacing will be determined in large part by the expected loading of sail 2.
• Mate ⁇ al 20 is cut into sectors 30, 31 of prepreg mate ⁇ al 20 of va ⁇ ous shapes and sizes, but typically t ⁇ angular and quadrilateral, as suggested m Fig. 2.
• Fig. 3 illustrates arranging t ⁇ angular sectors 30 with their edges slightly overlapping on to a first, imperforate film 32.
• Each sector 30, 31 has a length 34 and a width 36. the average length being substantially, typically at least about three to ten times, and more preferably at least about five times, the average width.
• First, longitudmally-extendmg reinforcement elements 24 are typically parallel to length 34.
• Pieces 30. 31 are sized, cut and arranged so that reinforcement elements, typically first reinforcement elements 24. will generally parallel expected load lines 28 when sail 2 is assembled.
• Fig. 4 illustrates a double layer of t ⁇ angular sectors 30 with the upper layer 38 not extending over the same surface area as the lower layer 40 Fig.
• Fig. 6 illustrates captu ⁇ ng sectors 30 between first film 32 and a second film 42.
• Pieces 30, 31 of reinforced mate ⁇ al 20 first film 32 and second film 42 may be laminated in any of a va ⁇ ety of conventional or unconventional fashions. If desired. additional adhesives may be used between films 32, 42.
• reinforced mate ⁇ al 20 may be made without any adhesive so that all the adhesive is applied as a separate step p ⁇ or to lamination. After lamination, the combination of sectors 30,31. films 32, 42 and the adhesive bonding the layers constitute an uncut sail section 44, typically generally rectangular in shape Uncut sail section 44 is then cut to the approp ⁇ ate shape to create a sail section 46 as shown in Fig.
• Sail body 3 in this embodiment, is made by assembling, typically broad seaming, four different sail sections 46 together along their adjacent edges 47
• sail 2 is also made from three different quad ⁇ lateral sail sections 46A. 46B and 46C
• Uncut sail sections 44 may be either flat laminated sections or they may be molded, three dimensional sail sections Figs. 8. 8A and 8B illustrate one method for transforming the stack of sectors 30 of prepreg mate ⁇ al 20 berween films 32 and 42. termed a mate ⁇ al stack 64. into uncut sail section 44
• Mate ⁇ al stack 64 is positioned between upper and lower flexible pressure sheets 66, 68 as shown in Fig 8 Pressure sheets 66. 68 are preferably made of a flexible elastome ⁇ c mate ⁇ al. such as sihcone, which provides high-f ⁇ ction surfaces touching films sides 32, 42 of mate ⁇ al stack 64 Upper ana lower flexioie pressure sneets 66. 68 are circumsc ⁇ bed by upper and lower rectangular frames 70, "2 Frames 70, 2 are mounted to upper and lower enclosure members 74. 76 Each enclosure member 74. 76 is a generally three-sided enclosure memDer with open ends 78. 80 Upper and lower enclosure members 74 76 carrying frames 70. "1 and flexible pressure sheets 66.
• a flexible elastome ⁇ c mate ⁇ al. such as sihcone, which provides high-f ⁇ ction surfaces touching films sides 32, 42 of mate ⁇ al stack 64
• Fig. 8A A partial vacuum is then created within a lamination inte ⁇ or 82 formed between sheets 66, 68 using vacuum pump 83. thus creating a positive lamination pressure suggested by arrows 84 in Fig. 8A.
• First and second end enclosure members 86, 88 are then mounted over the open ends 78, 80 of upper and lower enclosure member 74, 76 to create a sealed enclosure 90
• First and second end enclosure members 86, 88 each include a fan 92 and an elecr ⁇ c heater element 94.
• Fans 92 cause air or other fluids, such as oil, within enclosure 90 to be circulated around and over the outer surfaces 96, 98 of flexible pressure sheets 66, 68. This ensures that flexible pressure sheets 66, 68 and mate ⁇ al stack 64 therebetween are quickly and umformlv heated from both sides. Because the entire outer surfaces 96, 98 can be heated in this way, the entire mate ⁇ al stack 64 is heated du ⁇ ng the entire lamination process. This helps to ensure proper lamination. After a sufficient heating pe ⁇ od, the inte ⁇ or 100 of enclosure 90 can be vented to the atmosphere and cooled with or without the use of fans 92 or additional fans.
• perforated mold element 50 is made up of a number of relatively thin vertically-o ⁇ ented members 104 o ⁇ ented parallel to one another with substantial gaps therebetween to permit the relatively free access to the heated fluid to lower surface 98.
• no more than about 20%, and more preferably no more than about 5%, of that portion of lower surface 98 which is coextensive with mate ⁇ al stack 64 is covered or effectively obstructed by perforated mold element 50.
• perforated mold element 50 could be made of, for example, honeycomb with ve ⁇ ically-o ⁇ ented openings. Many dead spaces could be created withm the vertically-extending honeycomb channels, thus substantially hmde ⁇ ng heat flow to large portions of lower surface 98. This can be remedied by, for example, changing the air flow direction so the air is directed into the honeycomb channels, minimizing the height of the honeycomb, and providing air flow escape channels m the honeycomb near surface 98 Other snapes ana configurations for perforate ⁇ moid element 50 can also be used.
• the heated fluid within inte ⁇ or 100 which may be a gas or a liquid, is in direct thermal contact with upper ana lower surfaces 96.
• an interposing surface could be created between the heated fluid and surfaces 96. 98 So long as such interposing surfaces do not create a significant heat bar ⁇ er. the heated fluid will remain in effective thermal contact with outer surfaces 96. 98 of pressure sheets 66. 68
• first and second films 32. 42 may be made of the same or different mate ⁇ als. One or both films 32. 42 may not be imperforate.
• Section 46 may be joined by other than the broadseammg along adjacent edges 47, such as by conventional straight seaming or gluing techniques Any and all patents, patent applications and p ⁇ nted publications referred to above are incorporated by reference.

Landscapes

• Engineering & Computer Science (AREA)
• Combustion & Propulsion (AREA)
• Ocean & Marine Engineering (AREA)
• Sustainable Development (AREA)
• Sustainable Energy (AREA)
• Chemical & Material Sciences (AREA)
• Manufacturing & Machinery (AREA)
• Mechanical Engineering (AREA)
• Life Sciences & Earth Sciences (AREA)
• Laminated Bodies (AREA)
• Moulding By Coating Moulds (AREA)
• Woven Fabrics (AREA)
• Fats And Perfumes (AREA)
• Toys (AREA)
• Braking Arrangements (AREA)

Priority Applications (8)

Applications Claiming Priority (2)

Publications (1)

Family

ID=23553407

Family Applications (1)

Country Status (12)

Cited By (4)

Families Citing this family (12)

Citations (16)

Family Cites Families (27)

• 1999
  • 1999-09-10 US US09/393,132 patent/US6302044B1/en not_active Expired - Lifetime
• 2000
  • 2000-09-08 NZ NZ517004A patent/NZ517004A/xx not_active IP Right Cessation
  • 2000-09-08 PT PT00960075T patent/PT1216188E/pt unknown
  • 2000-09-08 DK DK00960075T patent/DK1216188T3/da active
  • 2000-09-08 AU AU71293/00A patent/AU758796B2/en not_active Ceased
  • 2000-09-08 AT AT00960075T patent/ATE238195T1/de not_active IP Right Cessation
  • 2000-09-08 CA CA002381282A patent/CA2381282C/en not_active Expired - Fee Related
  • 2000-09-08 EP EP00960075A patent/EP1216188B9/en not_active Expired - Lifetime
  • 2000-09-08 DE DE60002352T patent/DE60002352T2/de not_active Expired - Lifetime
  • 2000-09-08 WO PCT/US2000/024812 patent/WO2001017848A1/en not_active Ceased
  • 2000-09-08 ES ES00960075T patent/ES2197880T3/es not_active Expired - Lifetime
  • 2000-09-08 JP JP2001521607A patent/JP2004515393A/ja active Pending

Patent Citations (17)

Also Published As

Similar Documents

Legal Events