Abstract: A percussion primer composition including at least one explosive, at least one nano-size non-coated fuel particle having natural surface oxides thereon, at least one oxidizer, optionally at least one sensitizer, optionally at least one buffer, and to methods of preparing the same.

Abstract: A primer composition that includes stabilized, encapsulated red phosphorus, at least one oxidizer, at least one secondary explosive composition, at least one light metal, and at least one acid resistant binder. The stabilized, encapsulated red phosphorus may include particles of red phosphorus, a metal oxide coating, and a polymer layer. The metal oxide coating may be a coating of aluminum hydroxide, bismuth hydroxide, cadmium hydroxide, cerium hydroxide, chromium hydroxide, germanium hydroxide, magnesium hydroxide, manganese hydroxide, niobium hydroxide, silicon hydroxide, tin hydroxide, titanium hydroxide, zinc hydroxide, zirconium hydroxide, or mixtures thereof. The polymer layer may be a layer of epoxy resin, melamine resin, phenol formaldehyde resin, polyurethane resin, or mixtures thereof. A percussion cap primer that includes the primer composition, a tertiary explosive composition, and a cup is also disclosed, as are ordnance devices including the primer composition.

Abstract: A primer composition that includes stabilized, encapsulated red phosphorus, at least one oxidizer, at least one secondary explosive composition, at least one light metal, and at least one acid resistant binder. The stabilized, encapsulated red phosphorus may include particles of red phosphorus, a metal oxide coating, and a polymer layer. The metal oxide coating may be a coating of aluminum hydroxide, bismuth hydroxide, cadmium hydroxide, cerium hydroxide, chromium hydroxide, germanium hydroxide, magnesium hydroxide, manganese hydroxide, niobium hydroxide, silicon hydroxide, tin hydroxide, titanium hydroxide, zinc hydroxide, zirconium hydroxide, or mixtures thereof. The polymer layer may be a layer of epoxy resin, melamine resin, phenol formaldehyde resin, polyurethane resin, or mixtures thereof. A percussion cap primer that includes the primer composition, a tertiary explosive composition, and a cup is also disclosed, as are ordnance devices including the primer composition.

Abstract: A percussion primer composition including at least one explosive, at least fuel particle having a particle size of about 1500 nm or less, at least one oxidizer, optionally at least one sensitizer, optionally at least one buffer, and to methods of preparing the same.

Abstract: A non-toxic heavy-metal-free priming mix and a method of forming same, designed especially for industrial shotshells and other shotshells having abnormally heavy charges of propellant in an effort to qualify for heavy duty assignments such as the need to break up cement which has set up within a cement kiln and impedes the operation of the kiln. The mix is characterized by the inclusion of a secondary highly shock-sensitive explosive, PETN, in unusually large amounts such as 13-17% by weight of the mix as well as equally large amounts of powdered aluminum, as a fuel. This combination, supported by potassium nitrate and ferric oxide as primary and secondary oxidizers, respectively, proves to be highly effective. Each of the components, namely DDNP, PETN, tetracene, glass, powdered aluminum, potassium nitrate, ferric oxide, and gum tragacanth is non-toxic and heavy-metal-free.

Abstract: An electric motor, which is preferably a disk drive spindle motor, contains a multi-phase stator driven by switching the phases of drive current at corresponding commutation angles of the rotor. Small semi-random offsets are introduced into the commutation angles at which the drive current is switched, spreading the frequency of excitation over a wider range, and reducing the peak harmonic excitation at the switching frequency. Preferably, a table of offsets is maintained, and an offset from the table is added to each commutation point. The table preferably has more entries than the number of commutation points, the entries being cycled on a round-robin or other basis.

Abstract: A capacitor discharge retract system is provided for small disk drives wherein the small spindle size is incapable of generating enough electrical energy to enable conventional actuator retraction and the form factor is too small to accommodate capacitors of sufficient size to enable a conventional capacitive discharge system. A capacitive discharge retract technique is enabled using an elevated voltage, significantly above the disk drive supply voltage, to allow smaller capacitive storage elements to perform the function. The effectiveness of the system is further enhanced in those environments where a source of the required elevated voltage can be found already resident in the device circuitry where it was generated to support another function.

Abstract: Rotary actuator arc compensation correction method and apparatus are provided for a direct access storage device (DASD). A reference feedforward correction signal is generated at each of a plurality of sectors around a predetermined track on a disk surface. A specific selected track is identified, and both magnitude and phase of the generated reference feedforward correction signal are modified to correct for the arced trajectory caused by the rotary actuator at the specific selected track. Improved actuator servo control is provided by using pseudo sector compensation to interpolate the feedforward correction signal between servo sectors.

Abstract: A lead-free, heavy-metal free rim-fire priming composition consisting essentially of diazodinitrophenol (DDNP) as a primary explosive, a low percentage of a secondary sensitization explosive (tetracene), with a high percentage of abrasive (ground glass) and a very low percentage of an effective lead-free, heavy-metal-free oxidizer. A strong binder is added to aid in the installation and retention of the composition within the rim of the casings. A dye is also included for the sole purpose of facilitating visual inspection within the casing after installation of the composition within the rim. The high percentage by weight of the ground glass (46-60%) in combination with DDNP is of principal importance. The preferred mix is comprised of 29.8% of DDNP, 4.0 tetracene, 57.0% ground glass, and 7.5% potassium nitrate with 1.5% gum tragacanth added as a binder and 0.2% Prussian Blue as a dye.

Abstract: Rotary actuator arc compensation correction method and apparatus are provided for a direct access storage device (DASD). A reference feedforward correction signal is generated at each of a plurality of sectors around a predetermined track on a disk surface. A specific selected track is identified, and both magnitude and phase of the generated reference feedforward correction signal are modified to correct for the arced trajectory caused by the rotary actuator at the specific selected track. Improved actuator servo control is provided by using pseudo sector compensation to interpolate the feedforward correction signal between servo sectors.

Abstract: A demodulator system for identifying the position of a transducer assembly over a disk of a direct access memory device. The demodulator identifies alias cases and uses information placed in the boundary between tracks to generates a more robust indication of the location of the transducer assembly.

Abstract: A lead-free centerfire primer which, when fired, is devoid of serious toxic effects, and is characterized by the use of 5-20%, by weight, of barium nitrate as its oxidizer, in combination with 24-40% by weight of a primary explosive, 4-10% by weight of a sensitizer, 20-30% by weight of a nitrated ester, 4-10% by weight of an abrasive sensitizer, 4-7% by weight of a fuel, and 0.8-2.0% by weight of a binder.

Abstract: An apparatus and method for correcting for track misregistration when a slider or head assembly contains a separate read element and write element. The offset is determined at a first position and at a second position of the actuator arm assembly. From these offsets a constant and a multiplier are determined for determining an offset as a function of the cylinder location. Also disclosed is a method and apparatus for minimizing distance traveled to prevent misregistration when repositioning between the read element and a write element. The read element is intentionally offset from the write element at an angle so as to minimize the distance traveled across the disk.

Abstract: A reduced size brushless DC motor preferably for use as a disk drive spindle motor includes a rotor having two sets of permanent magnets, and a stator having separate portions corresponding to the two sets. An upper set of permanent magnets and the corresponding portion of the stator are located within the upper portion of the hub, which fits within the holes of the disks of a disk drive. A lower set of permanent magnets and corresponding portion of stator are located in the flange of the motor hub which supports the disks from below. In one embodiment, the stator core has an L-shaped cross-sectional area in the plane of the motor axis, one leg of the L driving the upper set of magnets in the rotor and the other leg driving the flange magnets. In a second embodiment, the stator core includes two separate pieces, one corresponding to each set of permanent magnets.

Abstract: A lead-free rim-fire primer mix which utilizes cupric azide, a highly sensitive chemical, as the primary explosive in lieu of lead styphnate. The cupric azide is mixed with carefully selected proportions of nitrocellulose, tetracene, fine particles of ground glass and a binder, typically gum tragacanth. When mixed in the proper proportions, this mix has the required sensitivity, stability, and non-hygroscopicity for regular commercial rim-fire ammunition. The tetracene is not required as a sensitizer, but is used as an ignition aid. The preferred range of percentages are 10-36% by weight of cupric azide, 5-10% by weight of tetracene, 15-30% by weight of nitrocellulose, 20-50% by weight of glass, and 1-2% by weight of a suitable gum.

Abstract: An improved non-toxic primer which is devoid of metallic oxidizing compounds and of hygroscopic compounds and is comprised of 30-75% by weight of at least two percussion-sensitive compounds selected from a group consisting of a diazo, a triazole, and a tetrazole compound mixed with approximately 10-30% by weight of a suitable propellant, and a frictionator comprised preferably of approximately 12% by weight of calcium silicide and 8% by weight of fine particles of glass. The glass preferably has a particle size of dimensions less than 0.0021". The primer provides improved propellant ignition, non-toxic ignition products, improved ballistic data, and greatly minimizes misfires.

Abstract: A non-toxic primer composition for center-fire cartridges which provides improved ballistic data and is void of metallic oxidizing compounds. It is comprised of a mixture of about 10-30% by weight of nitrocellulose and/or a double based propellant such as Hercules Fines, approximately 30-75% by weight of two percussion-sensitive compounds such as DDNP and tetracene, and approximately 10-30% by weight of calcium silicide. The mixture provides improved propellant ignition and non-toxic ignition products, and minimizes misfires in that it contains no hygroscopic compounds.

Abstract: A single-piece plastic shotshell casing and method of making same comprising softening one end portion only of a tube of uniformly biaxially oriented high density polyethylene sufficiently for forming and until a dollup is formed, then telescoping only a portion of the dollup into the rigid sidewalls of the tube, and then forming the dollup into a substantially thickened integral transverse base section constituting a head with a longitudinally extending primer opening therein, the base section being substantially biaxially oriented and the rigid sidewalls terminating a substantial distance inwardly from the outer end of the base section.

Abstract: A single-piece plastic shotshell casing and method of making same comprising softening one end portion only of a tube of uniformly biaxially oriented high density polyethylene sufficiently for forming and until a dollup is formed, then telescoping only a portion of the dollup into the rigid sidewalls of the tube, and then forming the dollup into a substantially thickened integral transverse base section constituting a head with a longitudinally extending primer opening therein, the base section being substantially biaxially oriented and the rigid sidewalls terminating a substantial distance inwardly from the outer end of the base section.

Abstract: A single piece plastic shotshell comprising a tube of high density polyethylene which is uniformly biaxially oriented to a substantial degree throughout its length and has side walls of constant internal diameter, thickness, molecular orientation and physical strength, the tube having a substantially thickened integral transverse base section formed of a compressed length of the tube at one of its end portions with a longitudinally extending primer opening therein, the base section being substantially biaxially oriented and telescoped within said end portion of the tube. Apparatus and methods for making the shotshell are also disclosed.