190 results about "Tangential point" patented technology

An apparatus for sampling ambient air to obtain coarse and fine fractions of particulate matter includes a single acceleration tube and a collection tube coaxially arranged along a central axis with a gap between facing distal ends thereof within a range of d / D1 of 1 to 2, wherein d is the distance or gap between the distal ends and D1 is the inside diameter of the outlet at the distal end of the acceleration tube. A housing surrounding the acceleration and concentration tubes is provided with a side-wall nozzle connected to a suction device for drawing a major portion of the sampled ambient air therethrough and for separation of particulate matter, as a fine fraction, from that major portion. A second suction device draws a minor portion of the sampled ambient air, containing the coarse fraction of the particulate matter, in a straight path approximating the central axis, through the acceleration tube and through the collection tube for passage through a filter for separation of the coarse fraction of particulate matter. The ratio of the flow rates of the major and minor portions of the sampled ambient air is adjusted to provide a cutpoint within the range of 2-3 microns. The apparatus is preferably operated with a flow rate for the sampled ambient air within the range of 900-1200 liters per minute.

A screw coupling for an oil well pipe, comprising a male screw pipe having a seal forming portion in a projectedly curved shape at the tip part of the pipe and a female screw pipe having a tapered seal part. The screw coupling is characterized in that, when the projectedly curved shape is brought into contact with the tapered seal part, a contact surface pressure Pc60 equivalent to 60% of the maximum contact surface pressure Pcmax applied to the contact surface is larger than an inner pressure Pi applied to the screw coupling and smaller than the proportional limit sigmar of the material of the screw coupling. The taper angle thetas of the tapered seal part is thetas >= thetat where the angle of a tapered screw is thetat, and the radius R of the curved surface of the projectedly curved shape is 90 to 170 mm or shorter. The angle thetas is 1.4 to 9.5 DEG at an apex angle, the axial length of the projectedly curved shape is at least 1.5 mm or longer on the front and rear sides of a tangent point, and the surface roughnesses H of the projectedly curved shape and the tapered seal part are 12 s or less.

A pipe structure comprising a length of a flexible pipe connected to an end fitting, the flexible pipe comprising an armour layer and an underlying pipe layer the armour layer, the underlying pipe layer having an outer surface around which armouring wires of an armouring layer are helically wound. The pipe structure provides a coupling between a flexible pipe comprising armouring wires and an end fitting, the coupling exerting a relatively low bending or flexure strain on the wires during normal operation of the flexible pipe. The transition path of an armouring wire between the flexible pipe and the end fitting comprises a straight-line-section between a wire-pipe-exit-point where the wire extends away from its underlying pipe layer and a straight-line-end-point on a support unit of the end fitting where the armouring wire in question has its first tangential point of contact. This has the advantage that in a loaded situation where the armouring wires will elongate elastically leading to a change in the helical angle of the armouring wires, the pipe structure will experience a slight twist and a controlled bending of the armouring wires on the surface of the support unit (due to a possible change in the base point of contact of the armouring wire with the support unit induced by the change of helical angle), thereby avoiding substantial bending of the individual armouring wires, which is of particular importance when the armouring wires are formed of a composite material. The pipe structure may be used in flexible pipes for the off shore transport of fluids (e.g. oil).

A nail having a plurality of grooves configured to reduce the amount of material needed to create the nail and increase the holding power of the nail, while only minimally affecting the bending yield strength of the nail and other important properties. The nail includes a relatively high number of grooves having a relatively shallow depth to retain a cross-sectional geometry of the shank that permits the formation of a full round head of sufficiently large diameter such that pull through resistance of the nail is not significantly affected. Various embodiments of such a nail are disclosed. In a first embodiment, the grooves are semi-circular and are disposed evenly and symmetrically about the circumference of the shank. In a second embodiment, a protrusion is formed at one tangent point (corner) of each of the plurality of grooves. In a third embodiment, a protrusion is formed at each tangent point of each of the plurality of grooves. In other embodiments the grooves may be unevenly and asymmetrically disposed about the circumference of the shank, the grooves may comprise non-semi-circular geometries and the grooves may comprise deformations.

A method for determining the shape of a scroll cage for a forward-curved centrifugal blower wheel in a blower housing having a blower cut-off end including determining the blower wheel dimensions, determining the blower wheel clearance, determining the distance from the center of the blower wheel to the discharge point of the scroll cage at the tangential point of the scroll cage and the blower housing, selecting a diffusing angle, calculating a development angle and plotting the scroll cage profile in polar coordinates. The method can include iteratively adjusting the diffusing angle and re-plotting the scroll cage profile and running simulations to determine the optimum profile.