GB2232140A - Wishbone boom mast collar for a sailboard - Google Patents

Abstract

A wishbone boom mast collar for a sailboard comprises a central flexible saddle to engage the rear of the mast and a pair of jaws to grip the mast when the sail is under tension. The front facing gap between the jaws is openable by leverage exerted by the boom arms to accommodate the mast. The collar is secured in position by a bolt passing through the jaws. <IMAGE>

Description

WINDSURFING APPLICATION. THE WISHBONE TO MAST CONNSOTION.

WISHBONE COLLAR This invention relates to THE WISHBONE COLLAR, A wishbone is composed of three sections; the front collar C, two spaceing pieces SP and an outhaul end OE, The front collar and spaceing pieces are usually presented as a complete unit. The outhaul end is removeable so that additional extention pieces XP, may be inserted to accomodate larger sails.

See dgm @ The purpose of the wishbone is two fold.

1. When assembled the wishbone is a rigid element, Using it as a compression structure, the sail may be correctly set by outhauling or tentioning in the direction indicated by the arrow in dgm 2.

2. It allows the saillon to ajust the position of the rig while stoo@ on either side of the sail. See dgm 3 The traditional wishbone passes round the front edge of the mast and is secured to the mast by means of rope or other patented locking system represented by the dotted line . See dgm 4 There are three major drawbacks to this system.

1.On the 'bow and arrow' principle the tentioned sail tries to froce the neck of the boom away from the mast. See dgm 6 2.Since in many cases the tention is high, the securing methanisms are prone to stretch. The resulting slop in the mast to boom connection makes handling the rig unconfortable and imprecise. Also the reduction in outhaul tention causes a loss in performance from the incorrectly setting sail.

3.If the securing machanism fails, (and in the majority of cases this is little more tnan a piece of three or four millimeter rope), the rig collapses, In extreme sea conditions this can be very dangerous.

According to the present invention, the mast to boom connection will be acheived by revearsing the collar on the wishbone, see dgm 6 The effett of tentioning or outhauling the sail will be to drive the mast hard into the back of the collar.

The collar which comprises a saddle and projecting arms is designed as a semi rigid structure, see dgm 7, The resulting flexibility allows the jaws of the collar to be slightly sprung. When sprung in the direction of the solid arrows, the jaws will open to accomodate the mast. When drawn together by the securing bolt the collar and compression insert will securely clamp the unit to the mast, See dgm 7 and 8 for plan and elevation.

Claims (3)

CLAIMS.

1.The compression froces incu@ed in the wishbone when outhauling the sail are resolved in the saddle area of the collar situated at the rack of the mast, See dgm 6

2.The invention is a semi rigid structure that is capable of flexing in the area of the collar, See dgm 7.

By applying a force in the direction indicated by the solid arrows, the jaws of the unit may be sprung to accomodate the diameter of the mast.

Releasing the force allows a return to the natural set position, Drawing the jaws of the collar together in the direction of the dottec arrows induces a clamping action.

3.The clamping action, A compression block is inserted in the open jaw of the collar. The block is located ore luggs that project inwards from the leading edge. The relieved face of the block mirrors the curvature of the mast.

A boit passing through the open jaw of the collar is drawn up onte a secured captive nut and the induced clamping action locks the unit firmly into position around the mast.

A high friction compression insert in the saddle area of the collar assists the clamping effect.