Showing papers by "Aetna published in 1985"
Patent•
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TL;DR: In this paper, a mill installation comprises a cross roll piercing mill for piercing and initially elongating a solid cylindrical billet, followed by a second cross roll "piercer" which functions purely as an elongator, and which functions to substantially elongate the pierced billet.
Abstract: The disclosure is directed to a process and a mill installation for the production of seamless tubes of high quality, in production mills having relatively modest production requirements. The mill installation comprises a cross roll piercing mill for piercing and initially elongating a solid cylindrical billet. Preferably, but not in all cases, the cross roll piercer is followed by a second cross roll "piercer" which functions purely as an elongator, and which functions to substantially elongate the pierced billet, typically in conjunction with an increase in O.D. and reduction in wall thickness. As a key feature, the pierced billet, previously processed by either one or two cross roll piercer/elongators, is thereafter further elongated by means of a Diescher-type elongator, and most particularly a novel form of such Diescher type elongator incorporating a restrained mandrel bar feature. From the Diescher mill, the highly elongated tube is processed on a sizing mill for finish sizing and typically some additional elongation. Although the Diescher type elongator is a well known mill in a general sense, its use in the context of this invention is unique, as is its use in conjunction with a restrained mandrel. The new mill complex makes it economically feasible to install a seamless tube mill for the production of high quality tubing at production levels as low as 200,000-250,000 tons per year.
12 citations
2 citations
Patent•
25 Sep 1985TL;DR: In this article, a fast settling amplifier is used to phase lock a local clock to incoming data bits within a specified accuracy range, using no more than a few initial bits of the packet.
Abstract: A fast settling amplifier for use in a phase locking system operative to phase lock a local clock to incoming data bits in a packet of short duration within a specified accuracy range, using no more than a few initial bits of the packet. Phase locking is achieved by phase shifting the data packet bits relative to a local clock signal a fixed, non-integral fraction of a bit period until the phasing lies within the specified range. The phasing is then accurate enough to permit signal decoding with an open loop over the limited duration of the packet. The phase locking process is activated each time the beginning of a new packet is detected. A Manchester code is typically utilized as the representation of the signal upon which synchronization is achieved. The Manchester code or biphase signal is recovered from the telecommunications network by a fast settling amplifier that rapidly establishes thresholding to accurately distinguish between high and low level signal levels in the Manchester code while maintaining a well filtered signal level.
1 citations