The present invention provides a polymer ammunition cartridge having a primer insert having: a top surface; a bottom surface opposite the top surface; a coupling element that extends from the bottom surface, wherein the coupling element comprises an interior surface and an exterior surface, wherein the interior surface comprises: a transition region that transitions from the bottom surface to a second segment wherein the transition region has a radius of from 0.02 to 0.2; a first segment extending from the second segment and terminates at a tip, wherein the first segment has a first segment distance from 0.02 to 0.18 inches and the second segment has a second segment distance from 0.02 to 0.18 inches, wherein the second segment has a second segment angle from +3 to −3 degrees relative to the first segment angle and the first segment has a first segment angle from +6 to −6 degrees from perpendicular to the top surface; a primer recess in the top surface that extends toward the bottom surface; a primer flash aperture positioned in the primer recess through the bottom surface; and a flash aperture groove in the primer recess and positioned around the primer flash aperture and adapted to receive a polymer overmolding through the primer flash aperture.

An abradable composite material comprising a matrix of sintered metallic particles and non-metallic solid lubricants disposed within the interstitial spaces of the matrix is described. The abradable composite material is capable of being used with, e.g., titanium-alloy blades of a gas turbine at least in part because the abradable composite material does not cause excessive wear or damage to the blades of the gas turbine. Methods of forming the abradable composite material are also described.

An abradable composite material comprising a matrix of sintered metallic particles and non-metallic solid lubricants disposed within the interstitial spaces of the matrix is described. The abradable composite material is capable of being used with, e.g., titanium-alloy blades of a gas turbine at least in part because the abradable composite material does not cause excessive wear or damage to the blades of the gas turbine. Methods of forming the abradable composite material are also described.

A recoating unit for equipping and/or retrofitting a device for producing a three-dimensional object by means of selectively solidifying, layer by layer, of a building material in powder form. The recoating unit is configured, depending on its movement in the first direction or in its opposite direction, to receive building material in that chamber that is the trailing chamber in the respective direction of movement and to spread the building material received in the respective trailing chamber to a uniform layer by means of the respective trailing recoating element.

A recoating unit for equipping and/or retrofitting a device for producing a three-dimensional object by means of selectively solidifying, layer by layer, of a building material in powder form. The recoating unit is configured, depending on its movement in the first direction or in its opposite direction, to receive building material in that chamber that is the trailing chamber in the respective direction of movement and to spread the building material received in the respective trailing chamber to a uniform layer by means of the respective trailing recoating element.

The present invention provides an injection molded primer insert for polymer ammunition comprising: a top surface opposite a bottom surface; a primer flash hole aperture positioned in the top surface extending through to the bottom surface; a substantially cylindrical coupling element extending away from the bottom surface forming an interior surface inside the substantially cylindrical coupling element and an exterior surface; a primer recess in the top surface that extends toward the bottom surface, a primer flash aperture positioned in the primer recess to extend through the bottom surface, and a flange that extends circumferentially about an outer edge of the top surface, wherein the flange is adapted to receive a polymer overmolding.

One embodiment of the present invention provides a stamped metal primer insert for a polymeric ammunition cartridge comprising: a top surface having a stamped flange that extends circumferentially about an outer edge of the top surface; a stamped coupling element that extends from the flange to a coupling tip; a stamped inner coupling element from the coupling tip to a bottom surface, wherein the bottom surface is opposite the top surface; a stamped primer recess in the top surface that extends toward the bottom surface; a primer flash aperture in the primer recess through the bottom surface; and a groove stamped in the primer recess around the primer flash aperture adapted to receive a polymer overmolding.

A hopper and method for transferring raw material, which can prevent segregation due to the impact caused by falling of the raw material powder when different types of raw material powders are transferred. The hopper for a raw material powder according to one embodiment of the present disclosure includes: a hopper body having an inner space in which the raw material powder is stored and including an outlet which is formed through the lower end thereof and through which the raw material powder is discharged; a transfer pipe to which the raw material powder discharged through the outlet is transferred and which has a region, through which the raw material powder is transferred, divided into a plurality of regions; and a slide gate unit disposed between the outlet and the transfer pipe to open or close the transfer pipe while adjusting a degree of opening of the transfer pipe.

The present invention relates to apparatuses for distributing build powder in powder-layer three-dimensional printers (2) and for the collection of particulates of the build powder that have become suspended in the gaseous atmosphere in the vicinity of the build platform of the three-dimensional printer. These apparatuses include recoaters (20) that are particularly useful in providing uniform distribution of fine build powder across the width of the build platform or powder bed. The present invention also includes powder-layer three-dimensional printers (2) which comprise such apparatuses for distributing build powder and/or apparatuses for collecting such suspended particulates. The improved fine powder recoater (20) uses an ultrasonic transducer (30) to move powder through a sheet screen (28). The sheet screen (28) may be presented to the powder fed onto it in a narrow dispensing slot to limit the flow rate of powder from the dispenser and to provide control over the amount of powder dispensed. The width of the slot may extend to cover the entire build box fill zone. The ultrasonic transducer (30) is preferably adapted to periodically sweep through a range of frequencies during operation. The ultrasonic vibration system may be augmented with a low frequency vibration system. The dust collection system (160) draws air from the perimeter of the build box (172) down through the deck plate (170) of the printer (2) and out of the printer's housing (164) to an external dust collector (250).

The present invention relates to apparatuses for distributing build powder in powder-layer three-dimensional printers (2) and for the collection of particulates of the build powder that have become suspended in the gaseous atmosphere in the vicinity of the build platform of the three-dimensional printer. These apparatuses include recoaters (20) that are particularly useful in providing uniform distribution of fine build powder across the width of the build platform or powder bed. The present invention also includes powder-layer three-dimensional printers (2) which comprise such apparatuses for distributing build powder and/or apparatuses for collecting such suspended particulates. The improved fine powder recoater (20) uses an ultrasonic transducer (30) to move powder through a sheet screen (28). The sheet screen (28) may be presented to the powder fed onto it in a narrow dispensing slot to limit the flow rate of powder from the dispenser and to provide control over the amount of powder dispensed. The width of the slot may extend to cover the entire build box fill zone. The ultrasonic transducer (30) is preferably adapted to periodically sweep through a range of frequencies during operation. The ultrasonic vibration system may be augmented with a low frequency vibration system. The dust collection system (160) draws air from the perimeter of the build box (172) down through the deck plate (170) of the printer (2) and out of the printer's housing (164) to an external dust collector (250).