Abstract: A chair with adjustable seat height in which the height change, made to suit the size of a given occupant, will at the same time change the height of the back rest above the seat. The amount of rise of the back rest is arranged to be in accordance with the proportions of average people. There is a pivoting, four-bar parallelogram-type linkage which raises the back support relative to the seat as the seat is raised. The front part of the linkage is fixed in height while the rear part raises and lowers the seat back. The linkage is rotated upward at the rear of the chair by one pin in the middle of the linkage which rises with the seat. An additional movement is developed in the linkage by having it bent downward toward the rear of the chair. The movement developed is a shifting of the seat back rearward of the seat as the seat rises.

Abstract: A boat hull keel is disclosed which retracts into the boat hull on a fixed pivot. The pivot location is placed above the keel/hull bottom intersection, rearward of the major axis of the fully lowered keel and rearward of the keel trailing edge at the keel/hull intersection. The placement distances are large in terms of the maximum keel chord length. (measured at the keel/hull intersection.) This amounts to a novel location. The location of the pivot allows the keel rotation to create a change in the attitude of the boat hull.

Abstract: The following specification discloses a process and burner for combusting fossil fuels such as coal to provide low SO.sub.x and NO.sub.x emissions. The process includes pulverizing the coal together with an alkaline material, such as limestone in an amount calculated to provide an alkaline metal stoichiometric equivalent of one to seven times the stoichiometric equivalent of the sulphur contained in the coal. The resulting pulverized coal-limestone mix is then combusted under fuel rich conditions. For example, 25% of the theoretical air required to combust the coal is preheated and injected into the combustion zone together with the pulverized coal-limestone mixture. The primary or transport air is swirled to increase mixing and to stabilize the flame. Preheated secondary air is introduced to the combustion zone. The amount of the preheated secondary air amounts to approximately 40% to about 100% of the theoretically required air.

Abstract: A convertible sailboat/motorboat is disclosed which has capability for displacement movement under maximum speeds typical of the maximum for displacement boats as a function of their size, capability for semi-planing of the hull under sail propulsion, and capability for planing of the hull under motorboat propulsion. The key features are an extremely light hull weight, an engine located approximately amidships, and a deep retractable keel with an upper trim tab which upon retraction into the hull creates a large shift of center-of-gravity rearward for the boat. The keel is hinged at a point above and to the rear of the keel which imparts a large rear movement of the keel weight for motorboat operation upon its retraction. Performance under displacement sailing is uniquely enhanced with the combination of a low-weight, deep keel and the keel trim tab in the upper portion of the keel where slip reaction is generated with the addition of a minimum of extra heeling moment to that generated by the sails.

Abstract: An air field space heater for a fog dispersal system of the type having a plurality of heaters for generating heated air along an aircraft runway. The heater generates heated air and directs it in the form of air jets with properly controlled magnitude of momentum at various angles of inclination relative to the plane of the runway, the angle of inclination being adjustable for dispersing fog under a variety of wind conditions. One form of the heater includes two warm air projectors coupled to two combustors. A single source of thrust power operates two propellers, one for each combustor. The air from the propellers, warmed by the combustors, flows into a pair of elbow conduits which are pivotable to pivot the projectors about a generally horizontal axis for adjustment of the angle of inclination of the projected air jets. The elbow conduits include fixed, low-loss turning vanes, and provide an efficient system for projecting the two air jets at various angles and with minimum drag.