On October 29th 1971 Ray Holland, Jr. filed for a patent of an improved version of wind-formed flexible kite of the general type known as a "Scott Sled", which is a registered trade name that is held by Ray Holland. The one problem with this kite was it's tendency to collapse but designers are attracted to it's simplicity and area to weight rating.
As Ray Holland explained in his application for a patent (No 193,875). 'The kite design was hampered by the tendency of its fully billowed form to collapse at the leading edge in gusty air'.
One of the reasons the original 'Scott Sled' retained the three batten design of Allison's flexible kite.
Ray Holland's improvements solves the problem of collapsing and produces a flexible kite that stays open in the wind even when it is gusty.
The design provides the ability to build flexible Sled type kites of varied sizes.
The design incorporated longitudinal ribs that are elastic or spring-like which straighten out when the kite is in a flat position. The choice of suitable material for the ribs requires careful selection to suit the flexible kites size. The designer Ray Holland suggests slender birch dowels for small kites.
When the kite is in flight and billowing full of wind the curved ribs causes the upper leading edge and trailing edge to be raised relative to the mid-section.
The action of the curved ribs further improves billowing, holding the mouth of the kite open which prevents the collapse of the leading edge that leads to the kite folding in upon it's self.
The patent 3,767,145 covered many variations of the design, some are shown here. The use of a pressure-inflated tubes for the longitudinal ribs is also mentioned in the patent.