Self-contained, anti-backlash nut

When a company switches from a ball screw design to a low-profile lead screw assembly, they are looking to cut size, weight, and cost. An anti-backlash nut maintains precision, but levies a price: Nut assembly requires that the company fixture the lead screw and install each piece separately--a time-consuming task to be avoided.

Solution? A self-contained nut that assembles/disassembles as one unit. Interlocking tabs hold the nut halves together even as a biasing spring pushes them apart. Compressing the spring prior to lead screw engagement allows starting torque/load adjustment.

Clean-room compatible, the "Slim-Line" nut is made of self-lubricating, fiber-impregnated Delrin(R). Applications include photodeveloping and medical imaging equipment as well as business machines.

W.M. Berg, Inc., 499 Ocean Ave., East Rockaway, NY 11518, 516-596-1700.

Automotion International, Ltd., Bentley House, 7 Bentley Rd., Meltham, Huddersfield, HD7 3AP, England, Tel: +44 484 850 401, Fax: +44 484 854 150.

Self-cleaning sensor

Dirty lenses create problems for photo-electric devices. Sensors that offer a "marginal detection signal" can avoid downtime and help guarantee specifiedperformance.

Once the accumulation of dust exceeds a pre-determined limit, the sensor's alarm signal notifies the machine operator that cleaning is required. Better still, the signal--via plc--can trigger an air valve to clean the lens automatically.

Built-in trouble-shoot capability, designed to lower maintenance cost, is a standard feature on many Telemecanique photo-electric sensors.

Andrei Moldoveanu, Square D Company, Groupe Schneider, Box 27446, Raleigh, NC 27611, 919-266-8634.

Michel Rochon, Schneider Electric SA, 89, bd Franklin Roosevelt, F-92500 Ruell-Malmaison, France, Tel: +33 1 41 29 85 00, Fax: +33 1 41 29 89 13.

'Fit and forget' lubricator

Instead of a grease gun, try this adjustable lubricator. Its piston, plastic shell, and gas generator automatically dispense lubricant into a fitting at a uniform rate.

A rotary switch activates the unit's gas cell, generating hydrogen gas. As pressure builds, the piston forces grease or oil through the fitting, into the workpiece.

The unit can be set to dispense the complete volume of lubricant anywhere from one to 12 months. Additionally, it can be stopped and restarted if necessary.

Jeff Carlisle, SKF Corp., 1100 First Ave, King of Prussia, PA 19406-135, (610) 962-4300.

Jeroen Koppe, SKF Maintenance Products B.V., The Netherlands, Tel: +31 29 729 0390.

'Programmable cement'

Magnetorheological (MR) fluids are made of magnetizable particulates randomly dispersed in a carrier liquid. Because they respond to magnetic fields, creating particle chains that restrict flow, MR fluids have found application in dampers, clutches, and other devices that control the transmission of force or torque.

To make MR fluids even more useful, Lord Corporation has introduced proprietary additives which reduce settling and abrasiveness. These developments are helping enable new devices that can achieve demanding life expectancy requirements.

Ulrich Wedel, Lord GmbH, Im Niederfeld 4, 64293 Darmstadt, Germany, +49 (6151) 897151

Rick Butters, Lord Corp., 110 Corning Rd., Cary, NC 27511, 919-859-4911.