Abstract: A method of modifying compressive strains in formation of a pipe ring groove (16), in which a differential temperature profile is established across the pipe wall in a narrow bending locus (l3) corresponding to the ring groove position, and the material is bent to form the ring groove. The temperature differential creates a differential in elastic modulus between the inner and outer surfaces of the pipe material, modifying the strain induced in inner concave and outer convex surfaces of the ring groove during the bending step.

Abstract: A start-up sequence for a continuous process for producing oriented plastic tube is disclosed. A variable diameter extruder (112) is started and is set to extrude a start-up diameter tube (220) which is significantly over the diameter of a pre-expansion tube diameter of the continuous process. The start-up diameter tube (220) is passed to and engaged by a first haul-off tractor (122). The start-up diameter tube (220) proceeds through to and over an upstream plug (128). The large, start-up diameter of the extruded tube (220) at start-up facilitates passage of the leading end of the start-up diameter tube (220) over a deflated, expandable portion (212) or a non-expandable portion (210) of a partly expandable plug (210, 212), depending on the arrangement of the expandable portion (212) and non-expandable portion (210). The tube is then reduced in diameter for the continuous process of diametral expansion and circumferential orientation to occur.

Abstract: A method of modifying compressive strains in formation of a pipe ring groove (16), in which a differential temperature profile is established across the pipe wall in a narrow bending locus (l3) corresponding to the ring groove position, and the material is bent to form the ring groove. The temperature differential creates a differential in elastic modulus between the inner and outer surfaces of the pipe material, modifying the strain induced in inner concave and outer convex surfaces of the ring groove during the bending step.

Abstract: The invention relates to a hard drive dock (HDD) including a HDD enclosure having a first HDD outer surface and a second HDD outer surface. Each of the first HDD outer surface and the second HDD outer surface have disposed within an electrical connector configured to electrically connect to a releasably attached hard drive pod (HDP). The HDD includes a bridge circuit disposed within the HDD enclosure. The bridge circuit is configured to provide a communicative interface between the releasably attached HDP and the computer data bus connection. The HDD is mechanically configured to accept a releasably attached hard drive pod (HDP) on either or both of the first HDD surface and the second HDD surface. The invention also relates to a HDD enclosure having two or more HDD outer surfaces. The invention also relates to a releasably attached hard drive pod.

Abstract: A method of modifying compressive strains in formation of a pipe ring groove (16), in which a differential temperature profile is established across the pipe wall in a narrow bending locus (l3) corresponding to the ring groove position, and the material is bent to form the ring groove. The temperature differential creates a differential in elastic modulus between the inner and outer surfaces of the pipe material, modifying the strain induced in inner concave and outer convex surfaces of the ring groove during the bending step.

Abstract: A continuous process and apparatus for producing oriented plastic tube comprising the steps of extrusion, temperature conditioning, diametrical expansion and cooling, characterized by the step of inducing axial draw of the tube between first and second haul-off means located upstream of the expansion step.

Abstract: A method of expanding a tube of plastics material in which a longitudinally travelling tube is progressively diametrically expanded in internal fluid pressure in an expansion zone between an upstream plug and an expandable downstream plug. Expansion of the tube is controlled in response to parameters which directly or indirectly indicate variation in the relative velocity at which material is delivered to and removed from the expansion zone, such as detecting upstream velocity, early expansion diameter, axial force on a sizing device or the tube diameter just before the expansion zone.

Abstract: A radio frequency antenna arrangement comprising an array of radiating elements, such as radiating antenna patches, which are co-located in a circuit, such as a microstrip circuit, with feeder elements which couple electromagnetic radiation to the radiating elements. The antenna arrangement has an electrically conductive backplate located behind the circuit, which acts as a groundplane and which is separated from the circuit by a dielectric layer. To reduce electromagnetic interference from the feeder elements which could disrupt the antenna pattern an electrically conductive screen is located directly in front of the feeder elements of the circuit but selectively exposes the array of radiating elements. The screen is spaced from the feeder elements and is not electrically connected to the backplate so that the screen, feeder elements and backplate do not form a triplate structure.

Abstract: The invention provides, in a first form, an expandable plug for regulating pressure or flow within a tube. The plug has an inflatable bladder (12) for diametral expansion by internal fluid pressure introduced by inlet (14). The plug is reinforced by an envelope (26) of cords (28) which spread laterally upon inflation of the bladder to provide diametral support to the bladder. In a second form of the invention, an inflatable plug positioned in a tube of internal diameter d is controlled according to the equation P.sub.p =.DELTA.P+P.sub.d wherein P.sub.d is the internal pressure in the plug, .DELTA.P is the differential pressure across the plug and P.sub.d is the plug free expansion pressure for diameter d.

Abstract: A sizing sleeve for controlling the diameter of plastic tube includes pressurized sizing sleeve portions in which fluid is injected under pressure about the tube circumference to form a lubricating layer. Drainage zones axially separate and isolate adjacent pressurized portions to allow independent temperature and pressure control. Each pressurized portion has flow stabilizer reducing variations in flow responsive to changes in the lubricating layer pressure. The flow stabilizer may comprise a high pressure fluid source and high pressure drop constrictor comprising fine apertures, which may be formed as grooves milled into end surface of abutting sizing sleeve segments.