Clean polyurethane mixer

Polyurethane-molding processors traditionally rely on high-pressure counter-current mixheads to completely combine polyol and isocyanate prior to injection. But liquids emerging turbulently from the mixhead can splatter, reducing the quality of finished parts. The lightweight MX mixhead virtually eliminates that problem: Its flowpath downstream from the mixing chamber includes two divergent volumes to reduce fluid pressure and velocity, ensuring laminar mixture flow.

The mixhead's shot-control piston and its coaxial throttling sleeve and cleaning piston can all be operated separately via integrated hydraulic valves. Full extension of each element cleans out all reaction spaces in the mixhead. Separate constituent-flow throttles allow precise pressure control for difficult mixtures.

Marketing Communications Group, Hennecke Machinery, Polymers Div., Miles, Inc., Mobay Rd., Pittsburgh, PA 15205-9741, (412) 777-2000.

Ambidextrous switch

Captive terminal screws, accessible from beneath or from either side, help the 8400K2 rocker switch reduce inventory needs for power-tool or appliance manufacturers. Available in 7-A, 125-V or 4-A, 250-V versions, the switch accommodates screw-mount or trap-mount applications. Its all-plastic housing resists corrosion, dirt, and sawdust.

Customer Service Center, Eaton Corp., Aerospace and Commercial Controls Div., 4201 North 27^th St., Milwaukee, WI 53216, (800) 735-6265.

Non-contacting speed sensor

Not a Hall-effect device, this newly introduced sensor registers time-varying magnetic fields as the voltage across two elements of proprietary alloys. According to its manufacturer, the design resists stray magnetic fields better and thus delivers an order-of-magnitude improvement in accuracy over Hall-effect sensors.

That improvement in accuracy lets the device handle field oscillations between 1 and 15 kHz. Depending on the peak magnetic field strength, the sensor may be placed as far as 0.75 inch from its target.

Wolfgang Eggert, Vacuumschmelze Div., Siemens Components, Inc., 186 Wood Ave. South, Iselin, NJ 08830, (908) 494-3530.