Abstract: This invention relates to a process for preparing high purity dibromoneopentyl glycol which comprises: (a) charging a vessel with pentaerythritol, a first portion of aqueous HBr and a catalyst; (b) maintaining the liquid contents in the vessel at a temperature from 80.degree. C. to 130.degree. C. for 1 to 3 hours; (c) adding a second portion of aqueous HBr to provide a total HBr to pentaerythritol molar ratio of 1:3 to 1:6; (d) after the foregoing aqueous HBr addition, raising the temperature of the liquid content of the vessel to 120.degree. C. to 180.degree. C.; and (e) sweeping the headspace of the vessel during at least (b), (c) and (d) with an inert gas and removing the sweep gas and any vapors formed during the process from the vessel.

Abstract: There is disclosed tree trimmer apparatus for installation on a helicopter or the like including a boom hanging vertically downward from the helicopter carrying a plurality of circular saws arranged with their blades nearly adjacent over a length of at least twenty feet on the boom, which is attached to the helicopter in a manner to be constrained against rotation about a vertical axis and to have rotational movement about a horizontal axis at right angles to the normal direction of motion of said helicopter; the blades are preferably powered by a hydraulic motor with groups of five 24-inch blades being driven through belts by one hydraulic motor provided with hydraulic fluid under pressure from a pump in the helicopter. A foot at the bottom of the boom extends to the rear and permits the apparatus to be landed with the bottom of the boom on a landing surface by maneuvering the helicopter backward to lay the boom and saw blades on the ground in front of the helicopter.

Abstract: A hand-held, portable, electronic calculator assembly including a body with a gripping and covering member for making the calculator fully operable by the user with one hand and for covering the keyboard of the calculator to prevent damage to the keyboard or depression of the keys when not in use. The hand-held electronic calculator assembly includes a calculator body member having a front surface, the front surface containing means for receiving a covering and gripping member and containing keyboard means, a back surface opposite the front surface containing means for receiving and gripping the covering member, and a gripping and covering member adapted for placement on the back surface of the calculator to enable operation and holding of the calculator by one hand and for placement on the top surface of the electronic calculator for covering the keyboard.