Top down furling system

Abstract

An improved top down furling system includes one or more improved components. A lower rotary drive unit with a rotary tack swivel rotates against a fixed portion of the furler, or is configured to permit routing of the tack line below the unit. The system may include an anti-torsion cable constructed in a manner so as to be able to transmit torque without excessive tension applied to the cable. The system also may include an end terminal of the anti-torsion cable having a quick side mount or bayonet type connection to the rotary drive unit.

Claims

1. A release for use in a top-down furling sail system having an anti-torsion cable, a terminal receiving device for connection to the anti-torsion cable, and an end terminal on at least one end of the anti-torsion cable, the release wherein: the end terminal has outwardly extending lips, and the terminal receiving device has a receptacle for receiving the end terminal, the receptacle having undercuts to receive and releasably hold the end terminal lips so as to provide a tensiley and torsionally secure connection between the anti-torsion cable and the terminal receiving device.

2. A release for use in a top-down furling sail system according to claim 1 wherein the terminal receiving device further includes a spring loaded button adjacent the end terminal receiving receptacle for releasably retaining the end terminal in the terminal receiving receptacle.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a side schematic view of a prior art top down furling system.

(2) FIG. 2 is a side perspective view of a top down furling system according to this disclosure. FIG. 2A is a side perspective view similar to FIG. 2 accept for using an alternate method of attaching a lower drive unit to the bow of a boat.

(3) FIG. 3 is a perspective view of a cut section of an improved cable of the top down furling system of FIG. 2.

(4) FIG. 4 is a side perspective view of the top of the cable terminal and the lower rotary unit of the top down furling system of FIG. 2, illustrating how a button can be depressed to allow the cable terminal to be removed from the lower rotary unit.

(5) FIG. 5 is a view similar to FIG. 4, with an arrow showing how the cable terminal can be removed from the lower rotary unit.

(6) FIG. 6 is a front perspective view of the top of the cable terminal and the lower rotary unit shown in FIG. 4.

(7) FIG. 7 is an enlarged front view of the attachment of the cable terminal to the lower rotary unit in FIG. 6.

(8) FIG. 8 is a side exploded perspective view of the cable terminal and the lower rotary unit of the top down furling system of FIG. 2. FIG. 8A is a side exploded perspective view of the cable terminal and the lower rotary unit of the top down furling system of FIG. 2A.

(9) FIG. 9 is a side exploded perspective view of a halyard swivel of the top down furling system of FIG. 2.

DETAILED DESCRIPTION

(10) The top down furling system of this invention overcomes the shortcomings of existing systems in two primary aspects (although they can be used together or independently of one another). In the first, an anti-torsion cable 5 uses construction materials and techniques to be able to transmit torque without excessive tension applied to the cable. In the second aspect, an end terminal 9 has a quick connection so the furled sail can be easily disconnected for stowage or to connect another sail.

(11) The two improved aspects of the top down furling system work together to improve the ease of furling, reduce the overall weight of the system, and reduce the expense of manufacturing the components. By removing the requirement to over-tension the anti-torsion cable, the system can be much lighter duty and the bearings in the lower rotary drive unit and halyard swivel can be simplified and can run more freely. Because loads are less, lighter duty bearings can be used, which are more easily rotated than high load bearings. As an example, balls could be used which roll more easily than rollers and sealed bearings. Because the loads are less, the anti-torsion cable requires less torsion resistance of the anti-torsion cable to drive the halyard swivel. The tack, connected to a rotary tack swivel 21 in which the loads are separated from the primary bearing system 28 of rotary drive unit, provides further load reduction, with all its benefits of lower weight and less cost. Furthermore because the anti-torsion cable does not require excessive tension, the bonding of the cable to the end terminal can be manufactured to a lower strength, because it does not have to withstand such high load. Finally the side load or bayonet style attachment of the terminal on the anti-torsion cable gives a quick connection to the lower rotary drive unit, helping with sail take down, as well as quick sail changes. Because of the lighter tension loads on the system, the anti-torsion cable attachment components can also be manufactured to a lower strength and thereby be lighter. The halyard swivel design can take advantage of lower load requirements and provide a lower weight aloft. Illustrative embodiments of each of the foregoing aspects are described herein.

(12) As shown in FIG. 1, where conventional parts are labeled with an A suffix, and similar parts in this disclosure use the same numbering, but without the A, the main components of a top down furling system are the lower rotary drive unit 3, end terminals 9 and 69 at each end of an anti-torsion cable 5, and a halyard swivel 29 at the top for connection to the masthead 26.

(13) FIG. 2 shows the lower rotary drive unit 3 with removable hook attachment 30 which uses a wire gate 31 with biased attachment to provide a spring shut action. A clevis pin 32 inserts into one of two sets of hook mounting holes 33 so the hook 30 can be positioned in line or 90 degrees to the furling line entry points 34 shown clearly in FIG. 6. As shown in FIG. 8, the rotary tack swivel 21 is rotatably connected to the fixed drum portion 35 of the lower rotary drive unit 3. The fixed portion 35 stays fixed to the bow of the boat using some securing method such as the hook attachment 30, or a shackle or lashing (not shown). As shown in FIG. 2A and FIG. 8A, another means of fixing the lower rotary drive unit 3 to the bow 25 can include a bow loop attachment 30A secured around a cross pin mounted in the fixed portion 35.

(14) In this embodiment, the fixed portion is the outer race. In other embodiments (not shown), the fixed portion could also be the inner race or driven hub 24. In other embodiments, the fixed portion 35 may have components that are bolted or glued together. The rotary tack swivel could be a separate bolt-on piece fastened to the fixed portion. Bearings or a low friction bearing material are used to reduce the rotational force required for rotation. The rotary tack swivel balls 57 provide a low friction rotation of the rotary tack swivel 21 in relation to the top 56 of fixed portion 35. The spinnaker tack line 20 secures to the rotary tack swivel at one of the lashing eyes 36. Alternatively, the tack line 20 can secure to a pulley secured to the lashing eye 36 so the tack line length can be adjusted for sail trim. When the lower rotary drive unit is rotated using the furling line 23, the rotary tack swivel 21 can lag behind the furling sail because it is not connected to the driven hub 24 of the lower rotary drive unit. Once the sail is furled either completely or at least a large part, the tack of the sail 27 will often need to begin rotating to complete furling. Different sail shapes may not require this further rotation. The tack swivel bearing system 39 provides low rotating friction to let the tack line 20 continue to furl with the sail until completely furled. Because the rotary tack swivel 21 is not bearing on the driven hub 24 of the lower rotary drive unit 3, there is less load on the rotary tack swivel main bearing system 39. To mount the balls in the tack swivel bearing system 39, a ball loader plug 40 screws to the body of the rotary tack swivel 21.

(15) Anti-Torsion Cable Using a Layer of High Tensile Filaments.

(16) FIG. 3 shows a portion of the anti-torsion cable 5 attached to the end terminal 9 which connects to the lower rotary drive unit 3 and extending upwards to an end terminal attaching to the halyard swivel unit.

(17) The anti-torsion cable 5 uses a reinforcing layer of a braided or interwoven material that does not require excessive tension to transmit torque up the cable to the halyard swivel unit 29. In this embodiment, steel wire filaments are used in the cable construction. Each wire filament is stiff independently of the weave resulting in a reinforcement that provides torsional stiffness to the finished woven cable both in compression and in tension so the excessive tension is not required to resist torsion while furling. During construction, the wire mesh can be heated so it can adhere to inner and outer layers to provide further torsional stiffness, yet still allow the cable to be coiled for storage. The cost of steel as a reinforcement is much less compared to material such as PBO, Kevlar, Technora or Twaron.

(18) This cost is multiplied by each anti-torsion cable used for each sail in a racer's inventory. Because less tension is required on the anti-torsion cable, the size and strength all other connecting components can be less. This includes lower rotary drive unit 3, halyard swivel 29, masthead connections and bow or bowsprit connections. There would also be no need for 2:1 halyard systems to achieve high tension before furling. Less tension requirements also means that the bearings in the lower rotary drive unit 3 and the halyard swivel 29 can be lighter duty. Balls can often be used instead of high load carbon steel sealed bearings thereby providing a freer running system, more easily driven by the anti-torsion cable 5.

(19) Thus, the anti-torsion cable 5 is of composite construction and has an inner reinforcing braided layer of high tensile filaments which are also stiff in compression, extending helically in both directions to substantially increase the torsion resistance of the anti-torsion cable 5 without applying tension to the cable. The cable is flexible enough to allow the cable to be coiled along its length for storage.

(20) More particularly, the cable 5 includes a reinforcing braided layer 10 preferably comprising a plurality of reinforcing wires, bands or filaments extending in one or in two opposite helical or spiral directions around the length of the anti-torsion cable. These filaments, in compression and tension, oppose torsional forces exerted on the anti-torsion cable as a result of furling operations.

(21) Stainless steel has been found to be an effective material to manufacture the wires but other materials of suitable strength and stiffness could be used. By using steel wires or filaments which are stiff in compression and torsion, the number of filaments working to provide torsional stiffness doubles.

(22) The actual stiffness of individual and isolated steel wires before they are interwoven is greater than individual and isolated threads of textile fibers such as Kevlar further providing increased torsion resistance without tensioning the cable.

(23) In the illustrated embodiment, the core 12 is made of rubber. Rubber provides the flexibility needed by the cable, while at the same time aiding in its torsional capabilities. It has also been found effective to manufacture the core 12 from other materials, such as conventional braided nylon rope. The function of the core 12 is to be a flexible support for the reinforcing braided layer 10 so that the reinforcing braided layer 10 does not collapse upon itself when placed under significant torsional force. Thus, any material of suitable flexibility and compressive characteristics could be used. Indeed, core 12 could be provided and installed entirely separately from the rest of the components.

(24) The cable 5 as shown also includes a cover 13. While the cover 13 may be made separately and bonded to the braided layer 10 by adhesive, it is preferable to extrude the cover 13 directly over the braided layer 10 by a co-extrusion process, using a die of suitable configuration, through which the inner portion and molten thermoplastic are coextruded. The cover 13 is preferably composed of a relatively hard and somewhat flexible thermoplastic material having good resistance to the sun and oxidation, such as polyvinyl chloride. The primary function of the cover is to protect the braided layer from saltwater spray and prevent corrosion. Thus, any suitable materials or covering techniques could be used, e.g., wrapping. Even a cable 5 without a cover could function effectively although it would not likely have the desired durability depending on the environmental conditions.

(25) The use of a helical or spiral reinforcing layer has the advantage that the layer is very flexible lengthwise but provides substantial torque resistance. The pitch of the reinforcing layer may be decreased for added torsional resistance, or increased where less resistance is needed. As a specific example, for a foil having an approximate length of 31 feet, a stainless steel braid may be employed in which the braid comprises twenty-four bundles of wire, with eight wires in each bundle, and being braided at a 1.56 inch pitch. This results in a foil having less than one revolution of twist in maximum wind conditions.

(26) Quick Attachment and Release System of End Terminals.

(27) FIGS. 4-7 shows the location of a quick attachment and release system of the end terminal 9 for the anti-torsion cable to the lower rotary drive unit 3. A similar quick attachment and release system (not shown) can also be used to join the end terminal 69 to the halyard swivel 29. In this context, the lower rotary drive unit and the halyard swivel are both referred to as a terminal receiving device.

(28) FIGS. 4-7 also show a quickly operated connect/disconnect of the end terminal of the anti-torsion cable 5 from the lower rotary drive unit 3. This design permits the user to quickly disconnect the sail and anti-torsion cable 5 leaving the lower rotary drive unit 3 and halyard swivel 29 in place on the bow of the boat after lowering so that the same sail or another sail can be quickly loaded/unloaded much easier than with the pin and locking mechanisms currently used. Also, if the furled sail and lower rotary drive unit 3 and halyard swivel 29 are lowered and removed from the bow, the design allows a much easier and faster method of switching sail and anti-torsion cable than using pins and locking mechanisms currently used.

(29) As shown in FIGS. 4-7, the top portion of the driven hub 24 forms a receptacle 38 to connect the end terminal 9. The end terminal 9 has lips 19 that fit into undercuts 41 in the receptacle 38. These features could be machined into the end terminal or receptacle or components added to create a similar connection. The fit of lips 19 into undercuts provide tensional strength as the load is applied to the anti-torsion cable 5 while using the system. Additionally the receptacle length 42 and corresponding terminal provide leverage to drive the anti-torsion cable without over stressing the receptacle and terminal fit. This provides a better torque transmission as compared to the typical eye to fork joining by other furlers. Other means of creating lips or protrusions to fit in the undercuts on the receptacle could be used to accomplish the same quick attachment. To lock the end terminal 9 into the receptacle 38, a spring loaded button 43 is used at the entrance. If there are two entrances, a spring loaded button 38 is used at each end.

(30) The spring loaded button 43 is formed from a short cylinder with one end closed and rounded, the other end open. The open end also includes a flange for keeping the button within the opening in the driven hub 24 through which it passes. A spring is positioned within the cylinder, engaging the closed end of the cylinder and the drive sheave 4 beneath the cylinder so that the cylinder is biased by the spring so that the button is held in a position where the button extends above the surface adjacent the end of the terminal 9, as shown in FIGS. 6 and 7.

(31) FIGS. 6 and 7 show an entrance in the receptacle for the end terminal on both sides. The receptacle could have an entrance for loading and unloading the end terminal on one side only. There is at least one button on the receptacle deck that is spring loaded so that it can recess towards the receptacle deck 44 allowing the end terminal to slide out or into the receptacle. There may be a spring loaded button on each entrance to the receptacle or on only one side with a permanent block on the other side. Once the sail is furled and lowered onto the deck a quick disconnect allows sailors to easily change sails removing one sail furled on its anti-torsion cable 5 and installing a sail of different size, shape or weight. To remove the end terminal 9, the spring loaded button 43 is pressed towards the receptacle deck 44 as shown in the large white arrow. At the same time by moving the end terminal 9 over the button as shown in FIG. 5 by the black arrow, the end terminal 9 can continue to slide out of receptacle 38. To help with this sliding process the button portion of the spring loaded button material might be Delrin or other plastic. Loading the end terminal 9 into the receptacle is similar. The end terminal 9 is used to recess the spring loaded button 43 at which point the end terminal 9 can slide into the receptacle 38. Once the end terminal is inserted completely into the receptacle 38 the spring loaded button 43 pops up locking the end terminal 9 in place. Once in position, tension load on the anti-torsion cable 5 can be applied and met by the lips 19 fitting into the undercuts 41 in the receptacle 38. Torque load can be applied through the furling line 23 around the drive sheave 4 which rotates the driven hub 48 of the lower rotary drive unit 3 rotating the end terminal 9 and the anti-torsion cable 5. Once the sail is furled and lowered onto the deck a quick disconnect allows sailors to easily change sails removing one sail furled on its anti torsion rope and installing a sail of different size, shape or weight.

(32) The end terminal quick attachment and release system is described as part of the lower rotary drive unit. A similar quick attachment and release system could be used at the halyard swivel unit 29.

(33) Thus, the procedure in basic terms is as follows. Bayonet end terminal 46 is slid into socket 15 passing into open cavity 17. Bayonet end terminal 46 is rotated 90 degrees. Bayonet end terminal 46 is retracted and seated into receiving slot 18.

(34) FIG. 9 shows the halyard swivel 29 using a bearing system to provide a rotatable link between the masthead 26 and the anti-torsion cable 5 and end terminal 9 or bayonet end terminal 46. The halyard loop 45 is loaded into the halyard swivel 29 through twin slots 48 for connecting to the boat's halyard. FIG. 9 shows the inner race 49 aside the main body 50 in order to show how the halyard loop 45 is loaded. The halyard loop 45 is normally loaded while the halyard swivel 29 is already assembled by loading the halyard loop 45 from below once the end terminal 9 is removed. As shown in FIG. 9, the head loop 53 is loaded onto halyard swivel for attaching the head of the sail 20. Thus the head of the sail and the end terminal 9 can rotate together while the halyard connected to the halyard loop 45 does not rotate. The head loop 53 can pass through the fitting at the top of the sail which may be a metal ring or a webbing type strap or strop. As shown in FIG. 9, once passing through the sail, the loop is pushed into each of the grooves 52 in the cross pin 51.

(35) It is helpful to consider all components of the lower rotary drive unit 3 and the halyard swivel 29 in exploded views. FIGS. 8 and 8A shows the components of the lower rotary drive unit 3:

(36) 40 ball loader plug

(37) 21 rotary tack swivel

(38) 57 rotary tack swivel balls

(39) 56 top of fixed portion

(40) 9 end terminal

(41) 24 driven hub

(42) 43 spring loaded buttons

(43) 4 drive sheave

(44) 54 stripper

(45) 39 main bearing system

(46) 54 ball plugs

(47) 35 fixed portion

(48) 30 hook attachment (FIG. 8)

(49) 30A bow loop attachment (FIG. 8A)

(50) FIG. 9 shows the components of the halyard swivel 29:

(51) 49 inner race

(52) 45 halyard loop

(53) 59 halyard swivel bearings

(54) 54 ball plugs

(55) 50 main body

(56) 51 crosspin

(57) 58 retaining rings

(58) 53 head loop

(59) 69 end terminal

(60) Although the invention has been herein described in what is perceived to be the most practical and preferred embodiments, it is to be understood that the invention is not intended to be limited to the specific embodiment, as set forth above. Rather, it is recognized that modifications may be made by one of skill in the art of the invention without departing from the spirit or intent of the invention and, therefore, the invention is to be taken as including all reasonable equivalents to the subject matter of the appended claims and the description of the invention herein.