초록 ▼

A manifolded, multiple-pin die apparatus and method processes potentially explosive material to form longitudinally perforated cylindrical pellets for use as gun propellants. A main entrance passage formed in mating manifold blocks gradually changes in cross-sectional configuration from circular to

A manifolded, multiple-pin die apparatus and method processes potentially explosive material to form longitudinally perforated cylindrical pellets for use as gun propellants. A main entrance passage formed in mating manifold blocks gradually changes in cross-sectional configuration from circular to figure-eight, and then branches in a gently curved manner. The divergent branches formed then further branch in the same manner and feed circular cross-section passages leading to extruding dies wherein a series of die pins extend axially through a discharge passage. Each die comprises a central core member supporting an outer shell via radial ribs which are configured to form flow passages of hour-glass configuration. No change of flow direction in the entire apparatus exceeds fifteen degrees.

대표청구항 ▼

In a system for receiving plastic material extrudate from a mixer or other source of flow under pressure and discharging the material in a plurality of cylindrical configurations, each having a plurality of axially extending perforations: a. die channel means including a plurality of separate branch

In a system for receiving plastic material extrudate from a mixer or other source of flow under pressure and discharging the material in a plurality of cylindrical configurations, each having a plurality of axially extending perforations: a. die channel means including a plurality of separate branch lines; b. a plurality of downstream dies, each communicating with one of said branch lines; c. each die comprising a surrounding cylindrical body sleeve providing an axially extending passage means with an axially concentric entrance channel and reduced diameter discharge channel; d. an axially extending core portion having generally radially directed ribs connecting the core portion with the sleeve, said ribs separating said passage means into a group of circumferentially spaced upstream die passage portions with axially convergent marginal walls extending axially between the sleeve and core between said ribs to pass material to said discharge channel, said convergent walls comprising axially convergent radial surfaces on circumferentially adjacent ribs connecting the core portion with the sleeve which axially converge, there being also convergent, radially opposite, circumferential surfaces on the sleeve and core leading to and, with said radial rib surfaces, defining reduced metering openings for said die passage portions of generally frusto-conical transverse configuration; e. said ribs also separating said passage means into a group of circumferentially spaced downstream die passage portions extending downstream from said metering openings toward said discharge channel and having divergent marginal walls extending axially between the sleeve and core between said ribs, said divergent walls comprising axially divergent radial surfaces on circumferentially adjacent ribs connecting the core portion with the body which axially diverge, there also being axially divergent, radially opposite, circumferential surfaces on the sleeve and core; f. The core portion in each die further having a conically projecting portion at its axially upstream and downstream ends, upstream and downstream respectively of said ribs; g. a plurality of axially extending elongate pins extending from said core portion into said discharge channel to form said perforations as said material exits the discharge channel; and h. said sleeve surfaces, said rib surfaces and said conically projecting portions all extending at relatively shallow acute angles relative to the sleeve axis. The invention as defined in any one of claims 1, 10, 14, 15, or 17 wherein said plastic material extrudate is an explosive.