US3534700A - Adjustable jib sheet block - Google Patents

Description

United States Patent John K. Marshall 1 Stark Place, Stamford, Connecticut 06902 [2| Appl. No. 804,748

[22] Filed March 6, 1969 [45] Patented Oct. 20, I970 [72] Inventor [54] ADJUSTABLE JIB SHEET BLOCK 4 Claims, 3 Drawing Figs.

[52] U.S. Cl 1 114/204, 1 14/ l 01 [51] Int. Cl B63b 15/00 [50] Field ofSearch 1 14/39,

l0l,l02,l09, 111,112, 204

[56] References Cited UNITED STATES PATENTS 238,785 3/l88l Jensen 114/204 Primary ExaminerTrygve M. Blix Attorney-Sandoe, Hopgood and Calimafde ABSTRACT: The invention is a rig for quickly and easily adjusting a jib sheet lead block fore and aft while the jib is trimmed and drawing. The block is attached to a slide which rides upon a track. A pulley arrangement rigged below deck, provides the mechanical advantage required to move the slide and block against the pull of the sail. A shock cord is provided to aid in positioning the slide on the track when the pulley is adjusted.

Patented Oct. W76) TO R EYS

ADJUSTABLE .llB SHEET BLOCK BACKGROUND In sail boat racing, in order to effect the most efficient trim of the jib, it is often necessary to adjust the fore and aft position of the jib sheet lead block. It is further desirable to be able to adjust the position of this block when the jib is full and drawing, and to be able to adjust it to an infinite number of such positions in order that a precisely desired shape of the jib sail might be effected.

Such an adjustment has heretofore been difficult or impossihle when the sail was filled due to forces created by tension on the jib sheet.

Movable jib sheet lead blocks are common, however, such prior art devices have been deficient in that they have not provided means of moving the block against such forces, and have provided only a limited number of positions at which the block may be securely locked in place.

A primary consideration in the design of all sailboat rigging is that it have a minimum of clutter. The invention solves this problem by providing a simple but effective device, which is preferably mounted below deck.

It is therefore an objective of this invention to provide means for positioning a jib sheet block fore and aft over a selected range with the jib full and drawing,

it is another objective of this invention'to provide a means of positioning a jib sheet lead block at any position over a selected fore and aft range.

It is a further objective of this invention to provide a means for adjusting the fore and aft position of a jib sheet lead block, which means is positioned below deck, and which is mechanically simple, inexpensive, easily operated and easily repaired.

SUMMARY The invention is a device for moving and adjusting the position ofa slide mountedjib sheet lead block upon a fore and aft track, and is comprised basically of tackle means for adjusting the position of the slide on the track, including pulley means to permit the tackle rig to be positioned below deck. Resilient means position the slide on the track in response to adjustments made in said tackle means and a jam cleat or the like holds the tackle in the desired position.

The advantages of this invention are essentially the same as its objectives; it permits adjustment of the jib sheet block under conditions which previously had rendered such adjust ment impossible, and it permits the operator to position the block at any point along the track.

The operator can adjust the position of the block with a minimum of effort, and with minimum attention to the mechanism of the invention, which permits virtually uninterrupted observation of the sail throughout the trimming process.

The invention is mechanically simple, and may be mounted below decks to avoid clutter.

Other objectives, advantages, and various further features of novelty and invention will be pointed out or will occur to those skilled in the art from a reading of the following specification in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a top view of the deck of a sail boat equipped with an adjustable jib sheet block of the invention.

FIG. 2 is a side view of the device illustrated in FIG. 1 shown partly in section.

FIG. 3 is a partial end view of the device illustrated in FIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED I EMBODIMENT Referring now to FIG. 1, an adjustable jib sheet lead block arrangement, designated generally by numeral 1, is illustrated affixed to the deck 2 of a boat. A jib 4 is set and drawing under a wind indicated generally by arrow 6. The jib sheet 7 is attached to the elew 8 of the jib 4, and is led aft through a block 9 to a winch l0, and is thereafter secured to a cleat (not shown).

Block 9 is attached to a slide II which rides upon a track 12. In FIG. l, the jib sheet 7 is led generally downward from clew 8 to block 9, and then aft to winch 10, so that it exerts a force on block 9 having upward and aft components. Under these conditions block 9 will normally tend to be moved aft by tension on jib sheet 7.

Those skilled in the art will realize that sheet 7 may be led otherwise than aft from block 9, so that the lateral component of the force upon slide ll may be forward instead of aft. In any case this force may be of such magnitude that considerable mechanical advantage is required to move slide II. This mechanical advantage is supplied by a tackle rig.

Referring now to FIGS. 2 and 3, the tackle is comprised of a stationary block 23 and a moving block 20. Block 23 is held in a position below deck and slightly aft of the after end of track 12 by a bracket 24 which is bolted to the deck 2. Block 20 is equipped with a forward pin 22 to which one end ofa line I5 is attached. The other end of line 15 is attached to the forward end of the slide 11, and is guided forward from slide 11 over pulley 16 mounted to the forward end of track 12. The line 15 is then led down through an eye 17 in deck 2, and over a second pulley wheel 21 positioned below deck 2 to the forward pin 22 of block 20.

The tackle system includes a running line 25 which is secured to a pin at the after end of block 20. The line 25 is then led aft around block 23, forward around block 20, and aft through ajam cleat 26 which is secured to deck 2. As the fore and aft movement of slide II will correspond to the fore and aft movement of block 20, block 23 should be located at the after end of track 12 in order to permit full throw of slide 11 on track 12.

While the invention may be employed with most any known slide and track configuration, it is preferable that the slide be provided with antifriction elements to facilitate its movement upon the track. This is particularly true when sheet 7 is led off block 9 at a sharp angle to track 12. Slide 11 illustrated in FIG. 2 is of a well known variety which incorporates rollers 27 to engage horizontal flanges 12a of track 12. The cross-sectional shape of track 12 is essentially that of an l-beam.

Block 9 is a conventional pulley block, and is swivelly attached to an eye Ila which is a part of the slide ll. Block 9 is thus free to align itself uponjib sheet 7, in the usual manner, in response to the directional pull of the sail 4.

As there are times, such as when there is very little wind, that there is little or no force tending to move block 9 aft, a shock cord 13 is used to pull slide 11 aft and take up any slack in the tackle 20. One end of shock cord 13 is attached to the after end of slide 11, and the other secured to a fitting 14 on deck 2. To minimize chaffing, cord 13 is led over a pulley wheel 28 mounted on the after end of the track 12.

The rig of the invention as described is free running under all conditions, and can be easily adjusted. Block 9 can be moved forward or aft by simply pulling in or letting out on line 25, which can be quickly disengaged and locked in jam cleat 26. The operator is in position to observe the jib while adjusting the position of block 9, and his attention need not be directed away in order to secure tackle 20 and block 9 in the chosen position.

While the principles of the invention have been described in connection with the above specific apparatus, it is to be clearly understood that this description is made only by way of example and not as a limitation to the scope of the invention as set forth in the accompanying claims.

Iclaim:

l. A device for adjusting the fore and aft position of a fair lead block for a sail sheet along the deck of a sailboat, comprising:

a track affixed to a deck of the boat;

a slide riding along said track;

a fair lead block attached to said slide;

pulley means remote from said track and slide to move said block and slide along said track in opposition to forces normally exerted thereupon by the pull of said sail sheet, said pulley means having a moving block;

means to connect said pulley means to said slide including a line connecting said moving block and said slide, and a plurality of pulley wheels guiding said line from said slide to said movingblock;

means to bias said slide in opposition to said pulley means; 1

and means to secure said pulley means when said slide is in a desired position along said track.

0 shock cord connected between said slide and the deck of the boat, and means to guide said shock cord freely therebetween.

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