US3724412A

US3724412A - Mast for sailing vessels

Info

Publication number: US3724412A
Application number: US00147065A
Authority: US
Inventors: J Blecker
Original assignee: Individual
Current assignee: Individual
Priority date: 1971-05-26
Filing date: 1971-05-26
Publication date: 1973-04-03
Anticipated expiration: 1990-04-03

Abstract

A mast for sailing vessels which includes a pair of elongated spars secured together in laterally spaced relation with their longitudinal axes substantially parallel and with longitudinal median planes containing the major cross-sectional axes of the spars intersecting such that the spars are angularly related and improve air flow over the leeward side of a sail, a base support block for securing the mast to a boat in upstanding relation, and sail attaching means for attaching a sail to the mast longitudinally therealong.

Description

o United States Patent 1 [111 3,724,412

Blecker {451 Apr. 3, 1973 [s41 MAST FOR SAILING VESSELS 601,494 3/1898 Clapham ..114/90 [76] Inventor: Joseph G. Blacker 6101 Sheridan Road East Chicagd 111; 60626 Attorney-John A. Dienner et al.

[22] Filed: May 26, 1971 [21] Appl. No.: 147,065 [57] ABSTRACT 0 A mast for sailing vessels which includes a pair of Related Appllcatlon Data elongated spars secured together in laterally spaced [63] Continuatiomimpan of Ser No 869 457 Oct 27 relation with their longitudinal axes substantially 969 abandoned parallel and with longitudinal median planes containing the major cross-sectional axes of the spars intersecting such that the spars are angularly related and [2?] improve air flow over the leeward side ofa sail, a base support block for Securing the mas to a boat in [58] Field of Search ..l14/90, 39,102,103 i g relation and sail attaching means for [56] R f C d taching a sail to the mast longitudinally therealong.

e erences l e UNITED STATES PATENTS 14 Claims, 9 Drawing Figures 2,984,199 5/1961 Giewald ..ll4/l02 PATENTEDAFR3 I975 3 724 412 SHEET 2 BF 3 H ull l MAST FOR SAILING VESSELS This is a continuation-in-part from my copending application, Ser. No. 869,457, filed Oct. 27, 1969, and now abandoned and relates generally to sailing vessels, and more particularly, to a new and improved mast structure therefor.

BACKGROUND OF THE INVENTION Conventionally, the forward or luff edge of the mainsail on a sailing vessel is secured to the trailing or rearward edge of an upstanding mast. Aerodynamically, the action of the wind which causes the main forward motion of the sailing vessel acts against the leading or luff portion of the sail. When sailing windward, it is necessary for the sailor to tack, that is, to sail as close to the wind as possible in one direction, and then come about, head to wind, and sail at an angle of almost 90 from the first direction, thus zigzagging toward the direction from which the wind is blowing. The wind flowing over or past the leeward side of the sail creates a pressure differential across the sail which imparts a forward force component on the vessel against the direction of the wind. Because the action of the wind on the sail resulting in the forward force component is more critical when sailing windward than when the vessel is running with the wind, there exists a need for a mast capable of improving wind flow over the leeward side of the sail whereby to increase the forward force on the vessel when sailing in a windward direction. Known mast designs have failed to meet this need.

SUMMARY OF THE INVENTION One of the primary objects of the present invention is to provide a new and novel mast for sailing vessels and the like which substantially improves the action of the wind on an associated sail to effect a greater forward motion of the vessel when sailing generally windward.

Another object of the present invention is to provide a novel sailboat mast which, in a first embodiment, includes a pair of spaced elongated spars having their longitudinal axes parallel, and wherein the longitudinal median planes of the spars angularly intersect in a line spaced from and parallel to the spars such that the spars open outwardly toward their forward edge portions and provide greater wind action on the associated sail.

Another object of the present invention is to provide a novel sailboat mast of the type described having means for supporting a sail in operative position midway between the parallel rearward edge portions of the angularly disposed spars.

Another object of the present invention is to provide a novel sailboat mast which, in a second embodiment, includes a pair of spaced spars having their longitudinal axes parallel to each other and to the axis of a longitudinal center support member, and wherein longitudinal median planes of the spaced spars are angularly related to intersect in a line spaced forwardly of the mast such that the spars open outwardly in a rearward direction.

Still another object of the present invention is to provide a novel sailboat mast as next above described wherein the longitudinal center support member is positioned to effect a constriction in air flowing between the center support and either of the spaced spars and establish improved air flow over the leeward side of the associated sail.

In carrying out the objects of my invention, I provide in a first embodiment a mast assembly having a pair of elongated spars secured together in spaced relation with the longitudinal axes of the spars being parallel and with longitudinal median planes of the spars being angularly related and intersecting in a line spaced rearwardly of the mast such that the spars open outwardly toward their forward edge portions. A plurality of sail hooks are slidably supported along elongated slideways secured to the rearward edge portions of the spars for attaching a sail to the mast. A header block is secured to the upper ends of the spars and supports a pulley to receive a halyard thereover for use in hoisting the sail, and base support means are provided adjacent the lower ends of the spars for securing the mast to a sailing vessel in generally upstanding relation.

A second embodiment of my invention employs a pair of elongated spars secured in parallel relation to each other and to a longitudinally extending center support spar member disposed substantially intermediate the rearward edge portions of the spars. The spaced spars are positioned such that longitudinal median planes containing the major cross-sectional axes of the spars are angularly related to define a line of intersection forwardly of the mast. The spaced spars thus open angularly outwardly toward their rearward edge portion, and cooperate with the centrally disposed support member to improve air flow over the leeward side of the associated sail.

Further objects and advantages of my invention, together with the organization and the manner of operation thereof, may best be understood by reference to the following description taken in connection with the accompanying drawings, in the several figures of which like reference numerals identify like elements.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front elevational view of a sailing vessel mast constructed in accordance with one embodiment of the present invention;

FIG. 2 is a side elevation view of the mast illustrated in FIG. 1;

FIG. 3 is a transverse sectional view taken substantially along the line 33 of FIG. 2;

FIG. 4 is a partial rear elevation view looking in the direction of arrows 4-4 of FIG. 3;

FIG. 5 is a partial side elevation view looking in the direction of arrows 5-5 of FIG. 3;

FIG. 6 is a top plan view illustrating the header block secured to the upper ends of the spars;

FIG. 7 is a median sectional view of the header block taken along the lines 7-7 of FIG. 6.

FIG. 8 is a foreshortened front elevational view of a sail mast in accordance with another embodiment o the present invention; and V FIG. 9 is an enlarged transverse sectional view taken substantially along the line 9-9 of FIG. 8, looking in the direction of the arrows.

DESCRIPTION OF A. PREFERRED EMBODIMENT Referring now to the drawings, and in particular to FIGS. 1-3, a mast constructed in accordance with one embodiment of my invention is indicated generally at 10. The mast 10 includes a pair of elongated spars 12, each of the spars having a forward leading edge portion 14 and a rearward trailing edge portion 16. The trailing edge portions 16 comprise generally planar-surfaces extending longitudinally of the spars and disposed in normal relation to the planes of corresponding inwardly opposed surfaces 18 of the spars. Each of the spars 12 further has an outward surface 20 extending longitudinally thereof, the rearward portion of each outer surface 20 being normal to the plane of the corresponding rearward edge 16 and the forward portion of each outer surface 20 adjacent the corresponding forward leading edge 14 being curved as at 22.

The elongated spars 12 are secured together in fixed spaced relation through a plurality of generally transversely disposed longitudinally spaced brace members 24 suitably secured to and between the spars as best seen in FIG. 3. In assembled relation, the longitudinal axes of the spaced spars 12 are disposed in parallel relation with longitudinal median planes of the spars, considered parallel to and generally intermediate the inner and

outer surfaces

18 and 20, being angularly related such that the spars open outwardly toward their forward edge portions 14. In this fashion, the opposed inner surfaces 18 of the spars 12 lie in planes which are angularly related and intersect to define a line of intersection spaced rearwardly of the spars and parallel to the longitudinal axes of the spars. It has been found that an included angle of about approximately 70 between the inwardly opposed surfaces 18 of the spars is particularly suitable for carrying out the primary objects of my improved mast 10.

The spars 12 may be made of any suitable lightweight material such as aluminum, wood or Fiberglas, and preferably have transverse sectional configurations such that the major transverse dimension of each of the spars, considered in FIG. 3, has a magnitude equal to about five times the dimension of the minor transverse axis. The rearward parallel edge surfaces 16 are laterally spaced a distance substantially greater than the thickness of a conventional sail to be used with the mast 10. Noting FIG. 2, the upper portion of the forward edge surfaces 14 of the spars 12 may be angularly inclined in a rearward direction to reduce mast weight. For example, it has been found that providing a rear-' wardly inclined upper forward edge surface on each of the spars 12 beginning at approximately a midpoint 26 of about 1 to 2 considered relative to the vertical, will maintain the aerodynamic efficiency of the mast and effect a desired weight reduction.

The mast includes base support means for securing the mast to a sailing vessel in generally upstanding relation. The base support means comprises an elongated support block 28 of generally rectangular cross section received and suitably secured within rectangular recesses disposed centrally within the two lowermost brace members 24, the upper end of the support block abutting the lower surface of the third lowest brace member 24 as illustrated in FIGS. 1 and 2. The support block 28 may comprise a separable member secured to the spars 12 through the lower brace members 24, or may be formed integral with the lower end portions of the spars in a known manner such as in F iberglas manufacturing techniques.

Referring to FIGS. 1 and 2, taken in conjunction with FIGS. 6 and 7, a header block 30 is secured to the upper end portions of the spars 12 and serves to maintain the upper end portions in spaced relation. To this end, the header block 30 has. angularly related outer side surfaces 32 which are suitably secured to the adjacent inward surfaces 18 of the spars 12. The header block 30 rotatably supports a pulley 34 within a suitable recess 36 in the header block. The pulley 34 is rotatably supported on a support shaft 38 having its opposite ends retained within suitable bores in the header block such that the plane of the pulley is generally coincident with the median longitudinal plane of the mast 10. For purposes of manufacture, the header block 30 may be made of two opposed portions 30a and 30b haying a spacer 40 secured therebetween, the spacer 40 defining the aforementioned recess 36 to receive the pulley 34. The pulley 34 serves to receive a halyard 42 thereover for use in raising and lowering a sail on the mast 10 as will become more apparent hereinbelow.

The mast 10 further includes sail attaching means, indicated generally at 44, secured to the rearward edge portions 16 of the spars 12 for attaching a conventional sail to the mast longitudinally therealong. The sail attaching means 44 includes a longitudinally extending slideway 46 secured to the rearward surface portion 16 of each of the spars 12, the slideways extending generally from adjacent the upper end of the support block 28 to substantially the upper ends of the spars. Noting FIG. 3, each of the slideways 46 has a flat web portion and outwardly extending longitudinal edge portions 48, the web portion being secured to the rearward surface portion 16 of its associated spar 12 through suitable means such as longitudinally spaced screws 50. A plurality of slide members 52 are slidably supported on the slideways 46 for longitudinal sliding movement therealong. Each slide member 52 includes a slide plate having a generally C-shaped cross section with the parallel turned edge portions received over the edges 48 of the corresponding slideway. Each slide member 52 further includes a tubular portion 54 formed integral with or otherwise fixedly secured to the slide plate thereof such that the axis of the tubular portion is disposed in transverse relation to the longitudinal axis of the associated slideway 46 and parallel to the rearward surface portion 16 of the associated spar 12. The slide members 52 are utilized in pairs with the tubular portions 54 of the opposed slide members of each pair receiving cylindrical end portions 56 of a sailhook 58 such that the sail hooks are disposed in transverse relation to the elongated spars 12. The opposed end portions 56 of each sail hook 58 are fixedly secured within the corresponding tubular portions 54 of the associated slide members 52 through lock pins 60 secured within suitable openings in the tubular portions 54 and within radial bores in the hook end portions 56. The sail hooks 58 may be secured to the slide members 52 in any suitable manner, the illustrated tubular sleeves 54 and lock pins 60 being one preferred embodiment. Each of the sail hooks 58 includes a hook finger. portion 62 disposed midway between the rear edge portions 16 of the spars and adapted to be secured to the forward or luff edge of a sail as by being received through an eyelet in the sail or attached to a luff rope. The hook finger portions 62 of the sail hooks are made to extend rearwardly of the spars 12 a distance sufficient to prevent the forward or luff edge portion of a sail attached to the mast from rubbing or abrading against the slideways 46 and slides 52. It will be understood that I employ a plurality of sail hooks 58 and associated slide members 52 to provide a plurality of points at which the sail may be secured to the mast. Preferably, a resilient flat type leaf spring 61 is suitably secured to each sail hook 58, as by having one end fixedly secured within a slot at 63, such that the outer end portion of the leaf spring is urged to a position closing the associated hook finger portion 62. In this manner, the leaf springs 61 may be moved to allow the hook fingers 62 to be inserted through eyelets in the sail, and will retain the hook fingers within the eyelets until the sail is manually removed from the sail hooks.

Noting FIGS. 1 and 2, a transversely disposed spreader 64 is suitably secured to the spars 12 in transverse relation thereto. The spreader 64 has outer end portions cooperating with shrouds 66 having opposite end portions secured adjacent the upper ends of the spars 12 and at points generally equally spaced below the spreader for stabilizing the upper portion of the mast in a conventional manner.

Having thus described the elements comprising one embodiment on my sailing vessel mast 10, and assuming that the sail attaching means 44 of the mast are rigged with a sail in a known manner, the operation of my improved mast is briefly as follows. Further assuming forward movement of the sailing vessel to be in a reach direction, as when tacking, the spar 12 downward of the wind direction from the opposite spaced spar will create greater wind turbulance past the corresponding forward luff portion of the sail on the leeward side thereof and create a greater pressure differential across the sail than can be obtained with known conventional masts. The increased pressure differential results in a greater lift and forward force component on the vessel from the action of the wind and thereby effects increased forward speed of the vessel.

FIGS. 8 and 9 illustrate another embodiment of a sailboat mast in accordance with my invention which provides improved wind action on the leeward side of an associated sail for effecting a greater forward force on a sailboat vessel. The sailboat mast illustrated in FIGS. 8 and 9 is indicated generally at 72 and includes a pair of spaced elongated spars 74 which are mirror images of each other and are made of similar material to the above described mast spars 12. The spars 74 have inner opposed surfaces 76 each of which is generally planer and terminates at its forward edge in a curved forward surface portion 78 which, in turn, blends with a generally outwardly surface 80 to establish a cross-sectional configuration generally as shown in FIG. 9, the outer surface 80 and inner surface 76 of each spar intersecting to define a rearward edge portion 82. The spars 74 are secured in spaced relation by a plurality of longitudinally spaced transverse brace members 84 suitably affixed to the inner opposed surfaces 76 of the spars.

An elongated longitudinally extending center support spar 86 is provided intermediate the spars 74 and generally adjacent the rearward edge portions 82 thereof. The center spar 86 is supported in parallel relation to the spars 74 by attachment to the transverse brace members 84. The center spar 86 has a generally oval cross-sectional configuration, as shown in FIG. 9, and further serves to support sail attaching means on its rearward edge portion. While the sail attaching means may be of any conventional design, the embodiment illustrated shows an elongated C-shaped guide channel 88 which extends the full longitudinal height of the mast 72 and serves to receive generally T-shaped sail attaching brackets 90 for longitudinal sliding movement therein as is known. A header block 91 is secured to the uppermost ends of the spaced spars 74 and center spar 86, as shown in FIG. 8, and rotatably carries a pulley 92 adjacent the rearward edge of the center spar 86 to receive a halyard thereover for raising and lowering a sail on the center mast 86.

In assembled relation, the spaced spars 74 have their longitudinal axes in substantially parallel relation throughout the length of the mast 72 and are angularly related, as considered in the transverse cross-section of FIG. 9, such that planes containing the opposed inner surfaces 76 of the spars intersect in a line of intersection spaced forwardly of the spars. It has been found that an included angle beta between the planes of the inner opposed surfaces 76 of approximately 2030 provides significantly improved wind action on the associated sail as will be described hereinbelow. Preferably, the major dimension of the cross-sectional configuration of the center spar 86 is maintained at one-third or less of the magnitude of the major dimension of the cross-sectional configurations of the side spars 74, as considered in FIG. 9. Base support means comprising a support block or shaft 28 may be secured to the lower end of the mast 72 in similar fashion to the above described embodiment of FIGS. 1 and 2 for securing the mast 72 to a sailing vessel in upstanding relation thereto.

With the mast assembly 72 mounted on a sailboat and having a sail attached thereto, and with the sailboat moving in a reach direction so that therelative wind direction is as indicated by either

arrows

94 or 96 in FIG. 9, the spar 74 downward of the wind direction will reduce air turbulence over the forward luff portion of the sail on the leeward side thereof and create a greater pressure differential across the sail than can be obtained with conventional known mast designs. Simultaneously, air passing between either of the spars 74 and the center support spar 86 is restricted and effects greater back pressure on the leeward side of the sail with a resulting greater forward force component on the sail in the direction of vessel movement.

While preferred embodiments of my invention has been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made therein without departing from the invention in its broader aspects.

I claim:

1. A sailboat mast comprising a pair of elongated spars secured together in spaced relation to accommodate air flow therebetween and with their longitudinal axes substantially parallel, said spaced spars having opposed side surfaces which lie in planes intersecting each other to define a line of intersection spaced from the spars and parallel to the longitudinal axes of the spars, base support means secured to said spars adjacent lower end portions thereof for securing the mast to a boat in generally upstanding relation.

2. A sailboat mast as defined in claim 1 including a plurality of generally transversely disposed brace members fixedly secured to and between said spaced spars.

3. A sailboat mast is defined in claim 1 wherein said spars have forward and rearward edge portions, the planes of said opposed side surfaces being angularly related so that said spars open outwardly toward their forward edge portions.

4. A sailboat mast as defined in claim 3 including a header block secured to the upper spacedends of said spars, and pulley means rotatably supported by said header block and adapted tov receive a halyard thereover.

5. A sailboat mast as defined in claim 3 wherein each of said spars has a major transverse dimension of a magnitude greater than about three times the minor transverse dimension considered in the same transverse plane.

6. A sailboat mast as defined in claim 1 wherein the rearward edge portions of said spars are spaced a distance substantially greater than the thickness of a sail to be supported by the mast.

7. A sailboat mast as defined in claim 3 including sail attaching means supported by said spars, said sail attaching means comprising a longitudinally extending slideway secured to the rearward edge portion of each of said spars, and sail hook means slidably secured to said slideways for movement longitudinally therealong.

8. A sailboat mast as defined in claim 7 wherein said sail hook means includes at least one pair of slide members slidably supported in opposed relation on said slideways, and a sail hook disposed transversely to said elongated spars and having end portions each secured to one of said opposed slide members. I

9. A sailboat mast as defined in claim 8 including a header block secured to the upper spaced end portions of said spars, and pulley means rotatably supported by said header block and adapted to receive a halyard thereover.

10. A sailboat mast as defined in claim 3 wherein the angularly related planes of said spars form an included angle of about approximately therebetween, considered in a plane transverse to the longitudinal axis of the mast.

11. A sailboat mast is defined in claim 1 wherein said spars have forward and rearward edge portions, and wherein the planes of said opposed side surfaces are angularly related so that said spaced spars open outwardly toward their rearward edge portions.

12. The sailboat mast of claim 11 including a center support spar disposed intermediate said spaced spars and secured thereto generally adjacent the rearward edge portions thereof.

13. A sailboat mast in accordance with claim 1 1 wherein said spaced spars form an included angle of approximately 2030 therebetween, considered in a plane transverse to the longitudinal axis of the mast.

14. A sailboat mast as defined in claim 12 including sail attaching means secured to the rearward edge portion of said center support spar.

Claims

4. A sailboat mast as defined in claim 3 including a header block secured to the upper spaced ends of said spars, and pulley means rotatably supported by said header block and adapted to receive a halyard thereover.

8. A sailboat mast as defined in claim 7 wherein said sail hook means includes at least one pair of slide members slidably supported in opposed relation on said slideways, and a sail hook disposed transversely to said elongated spars and having end portions each secured to one of said opposed slide members.

10. A sailboat mast as defined in claim 3 wherein the angularly related planes of said spars form an included angle of about approximately 70* therebetween, considered in a plane transverse to the longitudinal axis of the mast.

13. A sailboat mast in accordance with claim 11 wherein said spaced spars form an included angle of approximately 20*-30* therebetween, considered in a plane transverse to the longitudinal axis of the mast.