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US Government As Represented by the Secretary of the Army

John R Schmidt

Paul J Conroy

Eric J Robinette

Raymond A Wildman

Andrew T Gaynor

A method of manufacturing and optimizing energetic propellant grains includes generating an optimal surface area to mass fraction burned ratio profile for a predetermined solid structure including propellant grains; using the profile as a target function of a topological optimization process to generate a 3D form of a propellant grain; developing a negative of the 3D form of the propellant grain; mixing and densifying the negative with an energetic material in an uncured form in a mixer to create a structure including the energetic material and embedded negative; and solvating the negative from the structure, wherein the negative comprises a 3D propellant grain. The developing of the negative of the 3D form of the propellant grain may occur using a predetermined material in an additive manufacturing process. The negative may be soluble in the predetermined material, and the energetic material may be insoluble in the predetermined material.

Propellant grain for optimizing the interior ballistic performance of a weapon

A manual data entry keyboard, having left hand and right hand clusters of keys, is separated medially by an interposed, auxilliary matrix of keys comprising an [m.times.n] array of keys, where m and n are integers--m at least 4, n at least 1. In one embodiment the matrix includes a [5.times.2] array of keys which serve as a numeric keypad, accessed by the index fingers and thumbs, obsoleting the [1.times.10] array of number keys commonly included with the QWERTY cluster in existing English language keyboard arrangements. Top row accessory characters may be entered without the shift and are grouped in clusters in the top row and positioned to reflect the order of entry of elements of these groups in the usual flow of data. Punctuation keys are clustered in the right hand area of the keyboard, and except for the period and comma, are readily accessed by the little finger. Columns of keys, additional to the [5.times.2] keypad may be included in the keyboard, either or both medially and/or laterally to the two columns of the [5.times.2] array. Such added columns may serve as cursor control and editing keys, arithmetic operator keys, numeric punctuation keys, etc. Numeric entry is facilitated in arrangements that provide the [0] and [1] keys in the bottom row to be served by the thumbs while all fingers maintain home position on the keyboard.

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Bel Air, MD, United States of America

John R Schmidt