The present invention comprises a rocket motor nozzle that replaces the fixed-wall throat with a "wall" created by injecting gas radially into the nozzle. By injecting gas into the flow of combustion products that are going through the nozzle, this will deflect the combustion product flow, restricting and accelerating such flow, just as a fixed-wall does in a standard nozzle. However, by using the "gas-wall" described herein, no erosion will result at the restriction area.

A double-walled tube assembly has an elongate inner tube of thermoplastic resin, and an elongate extruded outer tube of thermoplastic resin including a plurality of ribs having a constant height longitudinally of the outer tube and extending over the entire length of the outer tube, the ribs projecting toward the center of the outer tube. The ribs have distal ends fused to the outer perpiheral surface of the inner tube over the entire length of the inner and outer tubes. The rib width is from 0....

A thin-walled plate provided with at least one reamed hole for mounting the plate on a centering element which extends through the hole, the largest dimension of the reamed hole in one direction being smaller than the smallest dimension of the centering element in the same direction, and with at least two elongate perforations located adjacent, and at opposite sides of, the hole and spaced from the edge of the hole to define plate portions in the form of bars between the perforations and the hol...

A double-walled pipeline system for flow media with an inner pipeline conduit including fittings, such as, T-pieces, angles, or bends, and instruments, such as, valves, stopcocks, etc., and with an outer pipeline conduit arranged concentrically to the inner pipeline conduit. The outer pipeline conduit includes two-part fittings and instrument casings, so that continuously connected outer annular space is formed in the pipeline system.

A multiple walled metal chimney formed of a plurality of axially joined chimney sections each of which utilizes positionally captured spacer rings. Joint clamps are used to connect the chimney sections for formation of the complete chimney conduit. The spacer rings are positionally captured between annular shoulders formed in the inner and outer walls of the chimney sections to eliminate welding of the rings. The rings may include an expansion joint to allow circumferential expansion and contrac...

A body, having a substantially closed cell formed therewithin, has a projecting nozzle, externally threaded, for threaded engagement with the sparkplug hole in a gas engine cylinder head. The body has two passageways formed therein, each threaded, for admitting fuel into the cell and for mounting a sparkplug or such ignition device thereinto. The body nestably sets into the sparkplug cavity, in the cylinder head, and mounts fluid seals thereabout. Ports broached in walls of the cylinder head wat...

A mug consists of an outer body made of plastics and an inner body made of a metal. The outer body has a sloped circumferential wall defining a hollow cavity. A bottom plate is fixed with a bottom end of the outer body, having a plurality of seats spaced apart on an upper surface for supporting the bottom of the inner body. An anti-leak gasket engages with an annular groove provided around an upper opening of the inner body, which has its upper edge closely contacting with an annular groove of t...

An embodiment of the present invention is a process for semiconductor device having a silicon substrate. The process comprises positioning at least one field implant mask and field implanting a silicon substrate around a bipolar active region in a substrate such that boron atoms are blocked out of an active region, and only the field region surrounding said active area is implanted, said implanting such that a predetermined layout area of a semiconductor device does not need to be increased to c...

Thermoplastic multi-walled pipe which has at least two tubular members different in inside diameter and concentrically arranged, these tubular members being spaced and supported by a plurality of ribs so as to provide hollow portions therebetween. The bond strength between the inner end surface of the rib and the tubular member supported thereby is less than that between the outer end surface of the rib and the tubular member supported thereby, so the exposure of the inner tubular member is easi...

This fitting is designed to be applied to a flexible walled tank, of the type employed in aircraft to hold fuel or other liquids, to provide a reinforced opening for receiving attachments, such as, connectors, gauges, pumps, conduits, and the like. The fitting is composed of a plurality of layers or plies of fabric reinforced elastic material, certain layers being mechanically connected to each other and all of the layers being adhesively joined at contacting overlapped portions into an integral...