July 2007 Edition

40 YEARS OF MAN

1/2 Inch of Steel Protects Diving Crew from 900 psi Pressure at 2000 Feet

A 2-man deep-diving vehicle built by the Electric Boat Div. of General Dynamics Corp. for its underwater research program, and the undersea vessel which aided in the recovery of a hydrogen bomb from the Mediterranean last year both used HY-100 to fabricate their pressure chambers.

This high-strength nickel-chromium-molybdenum steel containing 2.25 to 3.50% nickel protects the crew of the General Dynamics “Star III” from the 900 psi pressure exerted by the sea at a depth of 2000' with a personnel pressure hull only 1/2" thick. The Lukens Steel Co., Coatsville, Pa., hot spun two 66" dia hemispheres from 1-7/8" HY-100 steel plates and heat-treated them. After heat treatment, the hemispheres were contour-machined inside and out to 1/2" thickness, maintaining the required sphericity and gage-tolerance for pressure stability. The 2 head shapes were joined by submerged arc welding to obtain a weld having high notch toughness.

Cooling without Frost to Minus 180°C In Open Air Aids Bell Labs’ Research

Cryogenic cooling in air without frosting of the sample aids research at Bell Telephone Laboratories which is using a “Cryo-Collimator” to cool semiconductor materials for light and electrical field effect studies, neutron activation, and surface interaction observations. The unit is particularly valuable in cooling samples where equipment space or sample motion precludes use of cryostats or similar closed chambers.

The portable unit stores 15-liters of cryogenic fluid in its dewars reservoir, gasifies it, and delivers 40 ft3/hr at temperatures to -180°C (-292°F).

Temperature Resistant Copper Alloy Helps Slash Transistor Cost by 50%

Development of a 25 watt NPN transistor, housed in a plastic encapsulant eliminating the conventional metal semiconductor case, has resulted in a cost of less than 40¢ for each transistor in large quantities. The former price in quantities of 1,000 or more was from 80 to 90¢ each.

Engineers at Bendix Corp. designed the transistor, called the B-5000, for an automated fabrication system. Additional savings were made through selection of a strong, temperature-resistant zirconium-copper alloy, Amzirc, for the heat transfer element and collector lead.

TurboTrains’ Wheel Guidance System To Use Ball-Bearing Screw Actuators

Gasoline-turbine-powered 120 mph trains, scheduled to being operations later this year between New York and Boston, need a special wheel guidance system.

Beaver precision ball-bearing screw actuators are a key part of the system which keeps the wheels tangent to curved or straight track; 2 actuators to each side of the wheel truck.

One end of each actuator is connected to the underside of the car and the other end of each pair of actuators is joined by a rotating pin through the bearing assembly. The actuators turn like a turnbuckle. A recirculating “train” of steel ball-bearings run in grooves of the helically-cut, matched groove nut and screw.

Rubber Nose Cone Closure Protects Equipment, Allows Quick Access

An ethylene propylene nose cone closure, with no metal or moving parts, protects missile instrumentation from outside dirt and moisture during the pre-launch period. It meets military specifications: tolerances allowed range from 0.07" to 0.006".

The closure provides a tight seal but allows quick access to the instrumentation and fast closure afterwards.

What do you think?
Will the information in this article increase efficiency or save time, money, or effort? Let us know by e-mail from our website at www.ModernApplicationsNews.com or e-mail the editor at pnofel@nelsonpub.com.