Abstract: An example resonating structure comprises a substrate, a resonator body, and an anchoring body for anchoring the resonator body to the substrate. The resonator body is doped with a dopant having a concentration chosen so as to minimize a second order temperature coefficient of frequency for the resonator body. The resonator body is operable in an in-plane mode of vibration and an out-of-plane mode of vibration.

Abstract: A medium caliber polymer-based ammunition cartridge has an insert forming a base end and engaged to a polymer body forming an internal propellant chamber. The polymer body is engaged at its forward end to a polymer nose which has a shoulder that transitions directly into a projectile opening. The shoulder is inwardly radially thickened to increase lateral support about a medium caliber projectile loaded into the cartridge. The thickness of the shoulder may vary along its longitudinal length. One or more crush seals may be integrally formed about an outer surface of the cartridge nose. The crush seals include an annular tip seal and one or more annular shoulder seals. Each of the crush seals deform into an obturating ring to form a seal between the outer surface of the medium caliber polymer cartridge and the inner walls of the firing chamber.

Abstract: Methods and systems are provided for a firearms suppressor adapted with blowout panels. In one example, the blowout panels may be configured to have a lower tolerance for pressure than the materials from which outer components of the suppressor are formed. During over pressure events of the suppressor, the blowout panels may rupture, thereby dissipating pressure in the suppressor.

Abstract: Methods and systems are provided for firearm muzzle brakes. In one example, a muzzle brake comprises: a body; a projectile entrance and a projectile exit; a gas-actuated valve biased toward the projectile entrance within an interior of the body; and a projectile opening of the gas-actuated valve arranged along a projectile path between the projectile entrance and the projectile exit.

Abstract: A long range jacketed projectile has a cavity defined in the base end of the projectile core that is substantially filled with polymer material during the jacketing process. The cavity is configured to lighten the core, which lightens the overall weight of the projectile, and move the center of gravity closer to the center of pressure when compared to a conventional long range projectile. The polymer jacket lightens the projectile weight, which when combined with the lighter core, allows the projectile to attain a flatter trajectory at increased maximum velocities.

Abstract: The present invention provides three piece primer insert for use in polymer ammunition comprising: an upper primer insert portion comprising an upper primer insert bottom portion, a substantially cylindrical coupling element extending away from the upper primer insert bottom portion; and an upper flash aperture that extends through the upper primer insert bottom portion, a lower primer insert portion in contact with the upper primer insert portion, wherein the lower primer insert portion comprises a lower primer insert top portion positioned adjacent to the upper primer insert bottom portion at a connection joint, a lower flash aperture positioned in the lower primer insert top portion and aligned with the upper flash aperture, and a primer recess that extends away from the lower primer insert top portion to an extraction flange and in communication with the lower flash aperture; and a connecting portion that secures the upper primer insert portion and the lower primer insert portion wherein the connecting po

Abstract: A medium caliber polymer-based ammunition cartridge has an insert forming a base end and engaged to a polymer body forming an internal propellant chamber. The polymer body is engaged at its forward end to a polymer nose which has a shoulder that transitions directly into a projectile opening. The shoulder is inwardly radially thickened to increase lateral support about a medium caliber projectile loaded into the cartridge. The thickness of the shoulder may vary along its longitudinal length. One or more crush seals may be integrally formed about an outer surface of the cartridge nose. The crush seals include an annular tip seal and one or more annular shoulder seals. Each of the crush seals deform into an obturating ring to form a seal between the outer surface of the medium caliber polymer cartridge and the inner walls of the firing chamber.

Abstract: A penetrating bullet, for use in an ammunition cartridge, has a jacket defining an internal volume and forming a closed base end opposite a nose end. A penetrator shaft is enclosed within the jacket and extends from the internal surface of the closed base end toward the nose end. Substantially filling the remainder of the internal volume is a core. The core is formed of two distinct regions, with a first stable region formed proximate the closed base end and extending to an intermediate location about the penetrator shaft. Forward from the stable region is a thermal region. The thermal region extends from the intermediate location to the nose end. The thermal region will ignite upon impact with a target to soften or otherwise weaken the target, allowing the penetrator shaft to more effectively penetrate deeper into the target medium.

Abstract: A method for uniformly sizing polymer-based cartridge necks in ammunition cartridges includes providing a neck sizer and aligning the polymer cartridge below the neck sizer. The cartridge is pressed into the neck sizer where the pressing step causes the cartridge neck to be compressed in the neck sizer so as to reduce the inner diameter of the cartridge neck to less than the maximum outer diameter of the bullet to be fired from the cartridge. The pressing step may also involve compressing excess polymer material from the cartridge neck through flutes in the collet die of the neck sizer to form external neck ribs about the outer surface of the neck. The neck ribs aid in concentrically aligning the polymer cartridge in the chamber of a firearm to improve accuracy of the bullet fired therefrom.

Abstract: The present invention provides a two piece and a three piece primer insert for ammunition piece. Each of the individual pieces may be formed by punching, pressing, stamping, molding, milling, coining, or by additive manufacturing. The individual pieces may be joined by clinching, pressing welding soldering, sintering, adhesive gluing, staking, and iterative addition by forming one piece into another piece.

Abstract: A system for reference clock frequency correction is described. The system comprises a compensation module configured to (i) receive, as input, an oscillator signal and one or more control signals, (ii) generate a compensation signal based on the oscillator signal and the one or more control signals, wherein the generated compensation signal is a discretized sinusoidal signal having a controllable frequency, and (iii) output the generated compensation signal. The system further comprises a mixer block configured to (i) receive, as input, the generated compensation signal and the oscillator signal, and (ii) generate an output clock signal by mixing the generated compensation signal with the oscillator signal. A soft-switching method to reduce the effect of quantization noise is further described.

Abstract: Methods and systems are provided for a firearms suppressor adapted with blowout panels. In one example, the blowout panels may be configured to have a lower tolerance for pressure than the materials from which outer components of the suppressor are formed. During over pressure events of the suppressor, the blowout panels may rupture, thereby dissipating pressure in the suppressor.

Abstract: A long range jacketed projectile has a cavity defined in the base end of the projectile core that is substantially filled with polymer material during the jacketing process. The cavity is configured to lighten the core, which lightens the overall weight of the projectile, and move the center of gravity closer to the center of pressure when compared to a conventional long range projectile. The polymer jacket lightens the projectile weight, which when combined with the lighter core, allows the projectile to attain a flatter trajectory at increased maximum velocities.

Abstract: An inducer and a submersible pump for pumping a slurry comprising solids and viscous fluids, the inducer mountable to the pump's drive shaft adjacent to and immediately upstream of an impeller mounted on said shaft. The inducer comprises a hub, two to four inducer blades extending outwardly from and wrapping helically around the hub, the hub and the inducer blades defining a plurality of channels A trailing edge of each inducer blade is positioned snugly adjacent to and in fluidical alignment with a leading edge of a corresponding impeller blade when the inducer is mounted on the drive shaft of the pump, such that a velocity curve of the slurry is smooth as the slurry travels from a leading edge of the inducer blades to the leading edge of the impeller blades.

Abstract: A MEMS device may include: (i) a lower cavity, including a first island, formed within a first layer of the MEMS device; (ii) an upper cavity, including a second island, formed within a second layer of the MEMS device; (iii) a MEMS resonating element arranged in a device layer of the MEMS device and anchored via the first and second islands; (iv) a first set of electrodes for electrostatic actuation and sensing of the MEMS resonating element in an in-plane mode that is arranged in the device layer of the MEMS device; and (v) a second set of electrodes for electrostatic actuation and sensing of the MEMS resonating element in an out-of-plane mode that is electrically isolated from the first set of electrodes and located in the first or second layer of the MEMS device, and wherein the out-of-plane mode is a torsional mode or a saddle mode.

Abstract: MEMS based sensors, particularly capacitive sensors, potentially can address critical considerations for users including accuracy, repeatability, long-term stability, ease of calibration, resistance to chemical and physical contaminants, size, packaging, and cost effectiveness. Accordingly, it would be beneficial to exploit MEMS processes that allow for manufacturability and integration of resonator elements into cavities within the MEMS sensor that are at low pressure allowing high quality factor resonators and absolute pressure sensors to be implemented. Embodiments of the invention provide capacitive sensors and MEMS elements that can be implemented directly above silicon CMOS electronics.

Abstract: An integrated pressurized pump shaft seal assembly for a submersible rotary fluid pump comprises an oil reservoir having a pressure equal to or less than the ambient pressure external fluids surrounding the casing, the oil reservoir feeding an oil pump impeller that is mountable onto, so as to be rotated by, the rotary fluid pump shaft. The oil pump impeller is in fluid communication with an internal volute diffusion element integrated into a pump component. The centrifugal oil pump impeller pumps oil from the oil reservoir to the seal chamber through the internal volute diffusion element so as to increase a pressure within the seal chamber to a positive pressure above the ambient pressure of the external fluids surrounding the pump housing.