New and Notable Product Design

Madonna, Phone Home

JABRA® FreeSpeak™ Bluetooth™ Headset: Latest rage on the streets of Hollywood is this wireless headset to connect with a user's belt-mounted cell phone. But for those of us not as beautiful or waiting for that next script, there are practical benefits. Bluetooth architecture allows wireless connection to a phone in an office environment at distances up to 30 ft. According to Dennis Schroeder, senior design engineer at Stuart Karten Design, space and power were key concerns. A Cambridge Silicon Radio Bluetooth Radio (see DN 3.11.2002, p. 117) was used because of its size and low power needs, giving longer battery life. Wearer comfort (lightweight, less than an ounce, and fit) was realized with a hard plastic spine, a flexible polyurethane front half, and day-glo gel speaker tip. Engineer: Dennis Schroeder, www.kartendesign.com. Enter 691

Hi Omi

CEIVA Logic Digital Photo Receiver. It's easier than ever for Grandma, Nana, Omi, Papa, and Grandpa to keep up with their children's children. The CEIVA digital receiver is an Internet-linked LCD photo frame that can show grandparents, or kids away at school, a series of family photos downloaded from the company's server. No computer is required—a built in modem automatically dials a local call every night to download any images posted during the day for a slide show the next day. Aimed at folks not used to computers (there is only one control button), design drivers were built for simplicity and reliability, not speed. But many features are available, including a sleep mode and display of weather reports, news, lottery numbers, or works of art, all programmed by the family from the website not the display. Enabling technology is a 32-bit Cirrus Logic 7212 processor with an embedded soft modem. Lead Engineer: Dean Schiller, www.ceiva.com, Enter 690

Wall of Sound

NEC Valuestar Computer: While you still can't talk back to your TV, you can listen in style to films and music with this computer's vibrating flat-panel display. Using SoundVu technology from NXT, two19-mm diameter moving coil exciters, one under each side of the LCD cover sheet, vibrate the 2-mm thick optical-grade acrylic, which is separated by 6 mm from the LCD surface. The sheet is driven as a distributed-mode loudspeaker panel within the display's structural footprint. NXT's Geoff Boyd notes the company's design software is vital to OEW customers, ensuring vibrations are not transmitted to the structure nor affecting the image. Exciter placement, panel material thickness, and acoustic foam use must be carefully tailored. How good is the sound? While no means an endorsement, after a demonstration in the Design News office, once-skeptical staff members went scurrying to their cubes for favorite CDs. Engineer: Geoff Boyd. www.nxtsound.com. Enter 692

Stable guide

Thomson MicroGuide. The Gothic arch raceway design of these stainless steel linear guides is aimed at maximum rigidity, stability, and roll moment resistance—especially important in single rail applications. The "ball control" recirculation path offers smooth, quiet linear motion, even at high speeds. This is particularly appropriate for wafer handling, electronic insertion, lab automation, inspection and measurement, and medical diagnostic equipment. Stainless steel construction is useful for clean room environments as well as other applications where corrosion is a main concern. This product is readily available "cut to specified length" and maintains industry standard dimensions for ease of interchangeability. (www.thomsonindustries.com) Enter 693

Anti-backlash nut leads

Thomson BSA XCM1800 Plastic Nut. This 3/16-inch XC Series nut with ActiveCAM™ is the newest member of the company's lead nut products. Capable of carrying 5 to 10 lbs, it is the smallest anti-backlash preloaded screw of its type. The XC anti-backlash lead nut has a rigid SST spacer, which behaves similarly to a solid pre-load, but self-compensates for wear. The high stiffness of the SST material results in minimal deflection without the need for high pre-loads in the assembly. The unique feature of this design is the camming surfaces on the biasing member. In operation, BSA engineers allow it to be rotated to fill whatever clearance develops due to wear of the internal translation threads. Because of the angles chosen for the camming surface, BSA's patented ActiveCAM will not "ramp down" under load. Only when wear at the thread interface of the nuts creates clearance will the cam advance to eliminate backlash. Naturally clean and corrosion resistant, it is particularly good for semiconductor and medical applications. (www.ballscrews.com) Enter 694

Table it in close quarters

Schneeberger NDN Frictionless Miniature Tables. These tables deliver high-speed precision motion and require external no preload. "It is ball-size preloaded," says Roy Corbeil, applications engineer. The NDN tables consist of the stainless steel lower base and upper saddle, a single brass ball cage, and stainless steel rolling elements, which are matched to 1 micron. Engineers designed the ball cages into a single U-shape design that eliminates cage drift. This construction provides play free, smooth motion with high load capacities, high corrosion resistance, and minimal need for maintenance or lubrication. These tables can be used in any design orientation and are well suited for applications requiring fast, accurate, and dependable motion control in confined spaces. Strokes range from 5-70 mm, load capacities from 5-85 lbs, lengths from 10-80 mm, and typical accuracies from 2-4 microns. (www.Schneeberger.com) Enter 695

As small as they come

Steinmeyer Miniature Ball Screw. The 3-mm diameter screw with 0.5-mm pitch is about as small as they come, and available with either a single or double nut. "The balls, 0.6 mm in diameter, are literally like specs of dust," says George Jaffe, executive vice president. When equipped with a spring-preloaded double nut, this ball screw compensates for torque variations due to inaccuracies in the ground thread. The result is a smooth motion with near constant idling torque. One complete turn of the motor moves the nut only 20,000th of an inch, giving fine motion control. Steinmeyer uses an internal ball deflector recirculation system as opposed to a conventional tube type so the screw can reliably attain a high speed of 4,500 rpm. (www.steinmeyer.com) Enter 696

Long stroke, tight space

SKF Miniature Profile Rail Guides. For unlimited stroke length in a limited space, these stainless steel guides might be the ticket. They sport smooth operation and high load carrying capacity. The rail guides range in size from a 7-mm rail diameter with a dynamic load rating of 860N to a 15-mm rail diameter with a long carriage of 5,830 N. Maximum permissible speed is 3 m/sec. One of SKF's selling points is what Wayne Greer, business manager for linear motion products, terms exchangeable components, "You don't have to buy a carriage and have it match a rail. You can just buy a carriage, mount it, and it will work just fine," she says. (www.skfusa.com) Enter 697

All in one, longer life

THK KR15 Guide Actuator. This actuator takes its name from its 15-mm mounting height. It contains a miniature LM Guide and miniature ballscrew on one stainless steel block. Position repeatability is given as 3 microns, position accurately as 20 microns, and running straightness is 10 microns. What really sets it apart is its circular contact design of four rows of balls constrained in two locations—giving less differential slip, less rigid requirements for the mounting surface, and an increase in load ratings. Because more balls contact the raceway, the load is evenly distributed, which translates into longer life. (www.thk.com) Enter 698