Designer's corner

Rubber-coupled driveline

Torque fluctuations, caused by reciprocating engine masses, vary the angular velocities of the Plymouth Prowler's driveline components. A "rattle" from u-joint, slip-yoke, and spline-interface backlash, occurred at start-up, idle, and shut-down.

Engine output shaft is hard coupled to the driveplate on the crankshaft flange, and flexible rubber couplings replaced u-joints within the propshaft assembly.

To solve the problem, the engine's output shaft was hard coupled to the driveplate on the crankshaft flange, and flexible rubber couplings replaced u-joints within the propshaft assembly. The couplings employ six steel bushings interconnected with a series of nylon windings to transmit the torque, while rubber absorbs shock loads in rotational, angular, andaxial directions.

Rubber couplings partially damp out torque peaks in the rotational direction produced from the engine, and prevent the tube of the propeller shaft from conducting noise.

John York, Huppert Engineering, 2655 Woodward Ave., Suite 375, Bloomfield Hills, MI 48304, (248) 333-0210.

Neon auto lighting

Neon-automotive lighting technology, more rigid than conventional neon tubing, has many design and styling advantages over incandescent systems.

Faster rise times, longer life, 30 to 50% less current draw and thinner profiles, make it power and space efficient. Styling options include: single smooth-lit appearance, so rear lights could wrap around corners while offering continuous illumination; 3-D contours and configurations; and 19-or 44-point jeweled lighting surfaces.

Pete Sisti, Corning Incorporated Lighting Dept., HPC-8, Corning, NY 14831, (607) 974-8062.

Fuel-leakage detector

Fuel system pressure sensor is either mounted on top of the fuel tank, or adjacent to the tank, connected by a short hose.

To reduce fuel vapors in the atmosphere, new automotive emission standards require sealed fuel systems. Fuel line pressure-sensing employs a single integrated circuit with micro-machined silicon diaphragm containing piezoresistors. Measuring the difference in pressure between the sealed-fuel system and the atmosphere, a change in pressure indicates a leak and activates a warning light on the dashboard.

To ensure durability in the fuel system's hostile environment, silicon nitride protects the circuitry, and sensing-bridge resistors are buried below the diaphragm's surface. The sensor package uses metal, glass, and solder to resist exposure to gasoline.

Honeywell Micro Switch Division, 11 West Spring St., Freeport, IL 61032, (800) 537-6945.