Rig for a sail carrying boat

Abstract: A rig for a sail carrying boat comprising a mast having an axially extending leech track, a sail comprising a bead shaped fore leech constituted by a longitudinally folded flat ribbon sewn to the front edge of the sail cloth inserted in said leech track and a rotatable boom secured to the mast by a pivotable joint and comprising means for securing the sail to the boom and means for rotating the boom so as to reef the sail.

Description: The present invention relates to a rig for a sail-carrying boat which includes a mast, a boom which is pivotally connected to the mast and a sail which has a luff, a leech and a bottom edge, said boom comprising a tubular body which extends from a first end near the mast to a second end remote from the mast and is defined by a top portion and a bottom portion, said tubular body including a longitudinal slot in its upper portion through which said sail can extend into a chamber formed therein, a bracket pivotally connecting the first end of said tubular body to said mast, a first end wall provided at the first end of said tubular body, said first end wall including a hole therein, a second end wall provided at the second end of said tubular body, said second end wall including a hole therein, a rod which extends through the chamber in said tubular body and through said holes in said first and second end walls and a hollow shaft rotatably positioned around said rod, the bottom edge of said sail being attached to said hollow shaft so that rotation of said hollow shaft around said rod during reefing will cause said sail to be wrapped therearound and become reefed. A rig of this type is disclosed in FR-A-2 341 483. In this prior art rig the first and second end walls provided at both ends of the tubular body forming a part of the boom are integrated with said tubular body. Both when the sail is set and when reefed, strong forces are exerted on the hollow shaft and the rod, and these forces have to be taken up by the end walls of the tubular body without substantial deformation of neither the hollow shaft nor the end walls because otherwise free rotation of the hollow shaft would be prevented. Therefore the tubular body and in particular the hollow shaft and the end walls of the tubular body have to have a considerable thickness. This means a great weight in a considerable height above sea level which is detrimental to good sailing characteristics of the boat. It is therefore an object of the invention to provide an improved rig of the type mentioned above having a boom construction of low weight but capable of absorbing considerable forces. According to the invention a boom satisfying this requirement is characterized in that said first and second end walls include first and second separate end plates positioned over the first and second end of said tubular body, respectively, wherein said rod extends through said first and second end plates and is tensioned by nuts which are screwed onto threaded ends of said rod for pressing said first and second end plates against said tubular body. When strong wind forces are exerted on the sail and these forces are transferred to the boom they will merely cause the hollow shaft to which the sail is secured to deflect, thus increasing the axial forces exerted to the ends of the tubular body. Since the tubular body is capable of absorbing considerable axial forces with a relatively small wall thickness, it follows that the total weight of the boom including the reefing apparatus can be reduced compared to that of the prior art boom. The reduction of weight is not only advantageous for economical reasons but also facilitates the operation of the boom during sailing. EP 0 076 878 discloses a reefing device which comprises a hollow mast having an internal cavity and a longitudinal slot through which the sail may be drawn into said cavity for reefing and storage and a longitudinally wind-up member disposed within said cavity. The wind-up member is preferably rotatable about a tensioned fixed central wire or rod so as to remove any need to tension the wind-up member itself. The invention will now be described in more detail with reference to an exemplifying non-limiting embodiment thereof illustrated in the accompanying drawings, in which Figure 1 is a side view of the lower part of a preferred embodiment of the rig of the invention, Figure 2 is a cross-sectional view of the luff of the sail illustrated in Figure 1, Figure 3 is a cross-sectional view of the rotatable boom illustrated in Figure 1, Figure 4 is a sectional view of the boom shown in Figure 1 illustrating the reefing mechanism, Figure 5 is a sectional view of the boom shown in Figure 1 and illustrating the outhaul and boom cover mechanism, and Figure 6 is a top view of the boom shown in Figure 1. The rig illustrated in Figure 1 comprises a mast 1 comprising at its rear side an axially extending metal profile 2 comprising a luff track 3. The rig further comprises a sail 4 having a luff 5 which will be described in further detail below and a similar leech 6. The sail 4 comprises horizontal pockets 7 sewn to the sail cloth and adapted to hold battens. The rig further comprises a boom arrangement, generally referred to by the reference numeral 8. The front edge of the boom arrangement 8 is connected with the mast 1 by a goose neck joint 9. A luff feeder 10 is secured to the mast 1 a short distance below the lower end of the metal profile 2. The boom arrangement 8 also comprises means for attaching thereto a kicking strap 11 and a mainsheet toggle 12. Aq will appear from Figure 2, the luff 5 of the sail 4 comprises a longitudinally folded ribbon 20, the folded parts 21 and 22 being attached to the edge of the sail cloth by sewing. A string 23 of a filler material is located between the folded parts so as to impart bead shape to the folded ribbon 20. The boom arrangement 8 comprises a rigid boom tube 30 having at its underside an inner wall 31 and an outer wall 32 defining there-between a separate compartment 33. A hollow shaft 34 comprising four longitudinally extending undercut grooves 35 is mounted rotatable on a wire rod 36 within the tube 30. The bottom edge of the sail 4 is secured in one of the grooves 35 so that the sail 4 will be wound on the shaft 34 when the hollow shaft 34 is rotated as will be explained below. The tube 30 is closed at its ends by end plates 37 and 38. The wire rod 36 extends through the end plates 37 and 38 and is tensioned by nuts 39 which are screwed onto threaded ends of said wire rod 36. A reefing drum 40 is attached to the shaft 34 at the end remote from the mast 1 and as will appear from Figure 4, a rope 41 is wound on the drum 40. The rope 41 passes around two rope sheaves 42 and 43, of which the former is located in the compartment 33 and the latter is mounted in a goose neck bracket 44 at the opposite end of the boom arrangement 8. At the front end of the tube 30 the sides of the tube are cut off at an angle of about 45° relative to the axis of the tube so as to form openings 45 therein. As will appear from Figure 3 the upper part of the tube 30 comprises a slot 50 which is laterally offset relative to the rotatable shaft 34. The longitudinal edges of the slot 50 comprise grooves 51, and a combined outhaul and slot cover ribbon 52 is mounted axially displaceably in the grooves 51. One end of the ribbon 52 is connected with an outhaul slider 53 which is mounted slidably over the slot 50 by means of steel ball bearings 54. A leech feeder 55 for the leech 6 of the sail 4 is secured to the outhaul slider 53. The ribbon 52 passes around the free end of the boom arrangement 8 by following a curved path provided thereon and extends into the separate compartment 33 in which it is connected with an outhaul rope 56 passing around a sheave 57 mounted in the goose neck bracket 44. A spring 58 having one end attached to the goose neck bracket 44 and the opposite end to the ribbon 52 serves to move the outhaul slider 53 and consequently the leech feeder 55 rearwardly when the sail 4 is unrolled from the boom. The reefing of the sail 4 is effected by hauling the rope 41 which will cause the drum 40 and consequently the shaft 34 to rotate and by simultaneously loosening the sail halyard. The rotation of the shaft 34 will cause the sail 4 to move down and to be wound on the shaft 34. At the same time the leech feeder 55 will move towards the mast and cause the outhaul slider 53 to move in the same direction, thus gradually causing the slot 50 of the tube 30 to be covered by the ribbon 52. After the desired reefing has been effected the outhaul rope 56 is fastened in taut condition so as to stretch the sail 4. The luff feeder 10 mounted on the mast 1 will guide the luff 5 of the sail 4 comprising the folded ribbon 20 into the tube 30 where it will be wound on the front end of the shaft 34. If it is desired to counteract any undesired changes of the shape of sail during reefing fillers, such as elements of a foamed plastics material may be secured to the grooves 35 of the rotatable shaft 34.

Claims: A rig for a sail-carrying boat which includes a mast (1), a boom (8) which is pivotally connected to the mast and a sail (4) which has a luff (5), a leech (6) and a bottom edge, said boom (8) comprising a tubular body (30) which extends from a first end near the mast (1) to a second end remote from the mast and is defined by a top portion and a bottom portion, said tubular body (30) including a longitudinal slot (50) in its upper portion through which said sail (4) can extend into a chamber formed therein, a bracket (44) pivotally connecting the first end of said tubular body (30) to said mast (1), a first end wall (37) provided at the first end of said tubular body (30), said first end wall including a hole therein, a second end wall (38) provided at the second end of said tubular body (30), said second end wall including a hole therein, a rod (36) which extends through the chamber in said tubular body (30) and through said holes in said first and second end walls (37, 38), and a hollow shaft (34) rotatably positioned around said rod (36), the bottom edge of said sail (4) being attached to said hollow shaft (34) so that rotation of said hollow shaft (34) around said rod (36) during reefing will cause said sail (4) to be wrapped therearound and become reefed, characterized in that said first and second end walls include first and second separate end plates (37, 38) positioned over the first and second end of said tubular body (30), respectively, wherein said rod (36) extends through said first and second end plates (37, 38) and is tensioned by nuts (39) which are screwed onto threaded ends of said rod (36) for pressing said first and second end plates against said tubular body (30). A rig as claimed in claim 1, wherein said hollow shaft (34) indudes an axially-extending groove (35) in which the bottom edge of said sail (4) is secured. A rig as daimed in claim 2, wherein said longitudinal slot (50) in the top portion of said tubular body (30) is laterally offset relative to said rod (36) therein. A rig as claimed in one of the claims 1 to 3, wherein said tubular body (30) provides axially-extending grooves (51) on the respective opposite sides of said longitudinal slot (50) therein, wherein a ribbon (52) is mounted in said grooves (51) to be movable therealong, wherein an out-haul slider (53) is connected to a first end of said ribbon (52) so as to be movable along said tubular body (30) with said one end of said ribbon (52), wherein a leach feeder (55) is connected to said outhaul slider (53), said leech feeder (55) being slidingly attached to the leech (6) of said sail (4), and wherein an outhaul rope (56) is connected to a second end of said ribbon (52), whereby reefing of said sail (4) causes said leech feeder (55), said outhaul slider (53) and said ribbon (52) to move along said tubular body (30) toward said first end thereof. thereby said ribbon (52) covering said slot (50). A rig as claimed in claim 4, including a spring (58) connected to said second end of said ribbon (52) to bias said ribbon (52) such that it uncovers said slot (50). A rig as claimed in claim 4 or 5, wherein said bottom portion of said tubular body (30) provides an axial compartment (33) which is separate from said chamber, and wherein said outhaul rope (56) extends into and along said axial compartment. A rig as claimed in claim 6, including a reefing drum (40) located in said chamber and connected to said shaft (34) adjacent said second end plate (38) and a rope (41) extending from said reefing drum to and along said axial compartment (33) to said bracket (44) and then downwardly and away from said tubular body (30).

Inventors: BRENHOLDT NIELS, PEDERSEN MOGENS, WIESEL GUNTHER, BRENHOLDT, NIELS, PEDERSEN, MOGENS, WIESEL, GUNTHER
Applicants: SAILTAINER DK A S, SAILTAINER DK A/S
Application year: 1987
Main classification: B63H9
IPC codes: B63H9