Simple CG measurement
When calculating pipeline dynamics, it's important to know the stresses
caused by cantilevered flow-control valve and actuator assemblies. But how do
you measure the center of gravity of such irregular objects? This simple rig
does the trick.
The Center-of-Gravity measurement apparatus uses twin strain-gauge scales and knife-edge-balanced platforms. An adjustable cradle aligns the flow-path center with the center of one scale. Knowing the distance between scales, and the readings of each scale, users find the CG location from a sum-of-moments calculation.
Frank Leany, Valtek Inc., 1350 N. Mountain Springs Pkwy., Springville, UT 84663, (801) 489-2343.
The FlashLED line of aluminum-bodied, water-resistant flashlights uses light-emitting diodes instead of an incandescent bulb. Options include red, yellow, green, blue, and IR LEDs of several wavelengths each. Applications include conventional illumination, darkroom safelights, and invisible lighting for IR goggles or cameras. Users can choose the beam width and intensity best suited to their application. For example, a safelight-level wide-beam red light illuminates an 8[x]10 photograph at 10 cm while a high-intensity focused IR model can illuminate a 3-m-square area at approximately 60 meter's distance. The 100,000-hr, solid-state lamps exhibit better shock resistance than conventional bulbs and run 15 times longer on a set of AA batteries.
Al Astor, Ledtronics, Inc., 4009 Pacific Coast Hwy., Torrance, CA 90505, 310-534-1505.
Rack-mounted electronics and certain PC-board designs use expanding clamps to secure components and provide a thermal pathway to the chassis. But conventional wedge-lock clamps sometimes arch instead of moving in parallel during actuation. The result is uneven distribution of clamping pressure and thermal conduction.
In contrast, the Isobaric Expandable Thermal Clamp uses a series of abutting slider links whose alternate ends ride in upper and lower channels. With the far link pin-secured to the lower channel, a screw pushing on the near link causes the entire chain of links to fold accordion-style, forcing the two channels apart. The design resists binding as well as thermal and pressure discontinuities. Its patent is available for license.
Val Hristake, 13 Brookwood Dr., Maplewood, NJ 07040, 201-763-6657.
Torque, vibration control
A marriage of elastomers and hydraulics, FluidlasticTorque Restraints (FTRs) show promise in alleviating structure-borne engine vibrations to aircraft cabins. FTRs consist of elastomeric engine mounts with integral reservoirs for non-toxic, non-corrosive hydraulic fluid and a rigid channel which forms a fluid path between them. The mounts are arranged so that engine torque compresses both reservoirs, while vertical motion expands one reservoir and compresses the other--pumping the fluid between them. According the manufacturer, by proper selection of mount design and fluid composition, the system delivers high static stiffness but low dynamic stiffness at a given frequency.
Thomas Guckert, Lord Corp., Mechanical Products Div., 1635 West 12th St., P.O. Box 10039, Erie PA 16514-0039, 814-456-8511.