An apparatus and method for pre-forming a metal strip, having an embossing tool and a strip edge chamfering tool, the embossing tool having an embossing roll having a cylindrical surface with a central embossing portion, and the strip edge chamfering tool having an edge chamfering roll having a recessed central section and side sections on each side of the central section, and an anvil roll, the edge chamfering roll and the anvil roll being configured to receive and pass the metal strip in a clearance formed between the rolls, the clearance having a reduced height in the side sections, which are located in a position where the longitudinal side edges of the metal strip will pass, so that the longitudinal side edges on each side of the metal strip, and on the embossed side of the metal strip become chamfered when being passed between the pair of rolls.

In order to provide an economical method for producing a weapon barrel, in which a considerable plasticisation of the barrel inner wall and thus of the twist profile is avoided when armour-piercing ammunition is shot, in particular in the case of an intense firing sequence, it is proposed not to introduce the twist profile of the weapon barrel into a barrel blank, the material of which has its end strength already as a result of hardening and tempering, but has a lower strength level (approximately 800-1000 MPa). Only once the twist profile has been formed by extrusion or hammering is the steel hardened and tempered to a predefined strength value >1000 MPa, and is the barrel blank that is provided with the twist profile mechanically processed further.

A process heat exchange rod for cooling or heating liquids in a process vessel. The rod may have a linear form and extend downward through an upper wall of the process vessel into proximity with the lower floor. The rod internally defines a circulatory flow path for the heat exchange medium, including an outer jacket and a flow diverter having a central through bore and external helical flutes. Heat exchange medium travels down through the central through bore and then back up through helical grooves formed between the flow diverter and the outer jacket, or vice versa. Accurate heating or cooling of the process fluid is attained by modification of the configuration of the heat exchange rod as well as the flow rate and temperature of the heat exchange medium. The components may be injection molded of a polymer, often transparent, having a high heat transfer coefficient.

A process heat exchange rod for cooling or heating liquids in a process vessel. The rod may have a linear form and extend downward through an upper wall of the process vessel into proximity with the lower floor. The rod internally defines a circulatory flow path for the heat exchange medium, including an outer jacket and a flow diverter having a central through bore and external helical flutes. Heat exchange medium travels down through the central through bore and then back up through helical grooves formed between the flow diverter and the outer jacket, or vice versa. Accurate heating or cooling of the process fluid is attained by modification of the configuration of the heat exchange rod as well as the flow rate and temperature of the heat exchange medium. The components may be injection molded of a polymer, often transparent, having a high heat transfer coefficient.

A method in accordance with the present application includes sending a raw tube from a drum to an unwinding side capstan while the raw tube is rotated around a central axis perpendicular to a winding shaft of the drum by rotating the drum and the unwinding side capstan about the central axis concurrently with unwinding of the raw tube from the drum holding the raw tube, on an inner surface of which multiple straight grooves along a longitudinal direction of the raw tube are formed with an interval in a circumferential direction, in a coil shape, to wind the raw tube around the unwinding side capstan, and drawing in which the unwound raw tube is drawn while the diameter of the raw tube is reduced, and then the raw tube is wound around the drawing side capstan to twist the raw tube and obtain an inner spiral grooved tube.

A stator for a downhole motor configured for use in a downhole environment. includes an inner tubular member formed from a first metallic material having an outer surface and a helically lobed inner surface, and an outer tubular member comprising a second metallic material that is different from the first metallic material. The inner tubular member is connected to the outer tubular member by compressive force passing from the outer tubular member through the inner tubular member to a rigid mandrel removably disposed within the inner tubular member. The inner tubular member and the outer tubular member form the stator of the downhole motor.

Threads are formed in situ throughout a bore of a sleeve inserted into a corresponding hole in a substrate. A sleeve having a bore is inserted into a corresponding hole of a substrate. A mandrel is rotated through the sleeve. The mandrel has a threaded ended; the threaded end rotating throughout the bore of the sleeve forms threads throughout the bore. Prior to inserting the sleeve into the corresponding hole of the substrate, the sleeve can be placed onto the mandrel. In this case, the mandrel has an increasing diameter at the threaded end thereof, such that the sleeve rests on the mandrel towards the threaded end thereof where the bore has a smaller diameter than the mandrel. The mandrel is then rotated out of the sleeve in a direction opposite the direction in which the sleeve has been inserted into the corresponding hole of the substrate.

A method in accordance with the present application includes sending a raw tube from a drum to an unwinding side capstan while the raw tube is rotated around a central axis perpendicular to a winding shaft of the drum by rotating the drum and the unwinding side capstan about the central axis concurrently with unwinding of the raw tube from the drum holding the raw tube, on an inner surface of which multiple straight grooves along a longitudinal direction of the raw tube are formed with an interval in a circumferential direction, in a coil shape, to wind the raw tube around the unwinding side capstan, and drawing in which the unwound raw tube is drawn while the diameter of the raw tube is reduced, and then the raw tube is wound around the drawing side capstan to twist the raw tube and obtain an inner spiral grooved tube.

A method of making a stator includes positioning an inner tubular member having an inner surface within an outer tubular member, installing a rigid mandrel within the inner tubular member, and applying a compressive force to at least one of the inner tubular member and the outer tubular member.

Flow paths and boundary layer restart features are provided. For example, a flow path comprises a flow path wall defining an inner flow path surface and an asymmetric notch defined in the flow path wall. The asymmetric notch comprises a first surface and a second surface and is asymmetric about a first line extending through an intersection of the first and second surfaces. Further, a flow boundary layer restart feature comprises a first surface extending inward with respect to a flow path surface of a flow path and a second surface extending inward with respect to the flow path surface. The second surface is asymmetric with respect to the first surface such that the first and second surfaces define an asymmetric notch. Additionally, a flow path wall may comprise an asymmetric notch that includes a flow expansion angle and a flow contraction angle that are unequal.