Browse Month: January 2016

Cooking out; working out

Design dynamics in grills and tools. What’s cooking?

The Genesis Perma-Mount (TM) gas barbecue brings Flavorizers to outdoor cooking. The Flavorizer system replaces old-fashioned lava rock or pumice stone with angled bars. These bars direct cooking fats away from the meat, while vaporizing juices and drippings for real barbecue flavor.

Three individually controlled burners light quickly with the touch of a button for direct searing or indirect slow roasting.

The unit’s stainless-steel gas-supply lines are hidden below the grill’s storage area that is enclosed with tempered-glass doors.

The grill is easy to assemble and install on a deck or patio or over the stump of a cut-off post-mount unit, according to Weber-Stephen Products Co.

Designing-in safety

Good design makes safety the centerpiece for gas grills from Ducane Co.

Take materials. Hoods and fireboxes are of all aluminum, with no viewing windows that can crack or shatter. Heavy-steel cabinetry stays stable.

Vis-U-Glo* safety system tells the user if the grill is lit, even in the brightest sunlight. Each grill is factory fire-tested.

Rotis-A Grate burner, which sears in juices with no flareups, allows the user to leave the grill unattended while rotissing.

Sure-grip handles are side mounted to keep arms clear of the cooking surface and heat when opening the grill.

Hansen Gas-Mate II safety plug snaps the gas line into the tank. No tools. No poor connections that can cause gas leaks. Quick disconnect is also available in natural gas.

Top-Ported burners give each burner its own lighter. No gas crosses over from one burner to another. Cordless power

A high-powered line of yard and garden grooming tools includes a trimmer/weeder, hedge trimmer and power blower. A hand-held variable-focus spotlight is part of the line from Toro Home Improvement Division.

The cordless products deliver at least 40 percent more power than any other cordless tools, according to Rob Beachy, marketing manager.

“We were very serious about performance when we designed the line,” says Beachy. “For example, the cutting speed on the cordless trimmer/weeder matches the speed on many gas-powered trimmers. It easily outperforms most of the corded products now on the market. “

The line is powered by a heavy-duty power pack. The tools plug into the pack through a standard cigarette-lighter connector. Any equipment capable of hooking into a car cigarette lighter can be run off the power pack, including stereos and vacuums.

The power pack is encased in a soft and flexible nylon-carrying case which can be adjusted and worn over the shoulder or on the chest, back or belt for maximum operator comfort. The pack weighs less than 7 lbs. and recharges overnight.

“This is the largest and most powerful battery you’ll find with cordless power equipment,” says Beachy. “It even has the power to run two of our competitor’s cordless power tools simultaneously.”

Another example of power is running time. With a single charge, Beachy says, consumers can:

  • Trim around an entire football field with the trimmer/weeder.
  • Manicure a 40-ft.-Iong hedge with the hedge trimmer.
  • Clear 60 ft. of sidewalk with the power blower.
  • Then use the halogen BriteLite to find all the tools left in the yard after dark.

Xerox snap roller/shaft assembly

Redesign of copier component was driven neither by marketing nor engineering. At most companies, repairmen fix machines, and that’s pretty much it.

Not so at Xerox.

There, repairmen sometimes go beyond the normal call of duty to provide Xerox engineers with solutions to recurring service problems.

In 1986, for example, Xerox service technicians found themselves regularly answering complaints concerning a roller/shaft assembly in a paper transport assembly, says Tony Polletto, technical specialist/project manager.

Because the paper transport assembly moves paper, paper dust and dirt can eventually collect in the rollers,” says Polletto.

“When that occurs, it breaks down lubrication and the machine starts to squeal. If left unattended, it jams.”

Manufacturing woes

Not only was the Xerox roller/shaft assembly a service headache, it was a challenge for manufacturing from the time it was developed in 1982.

To assemble, Polletto says the procedure went like this:

First an E-ring was placed on the inner groove of the shaft, followed by a washer, then a roller, then another washer, then another E-ring.

“So you were looking at four washers, four E-rings and two rollers per shaft. “

Once in the field, paper dust began getting in between the shaft and inner diameter of the roller, says Polletto.

When this led to service problems, the component’s design was as cumbersome for Xerox service technicians to take apart, as it was for manufacturing to put together.

“A repairman would have to pull an E-ring in order to pull everything else off,” says Polletto.

E-rings are not easy to change and the paper transport assembly is one area where you don’t want loose E-rings. A loose E-ring could drop and rip photocopies. And customers tend to be rather sensitive when it comes to their copies.”

Teamwork encouraged

Service technicians investigating the ins and outs of a possible redesign is no fluke at Xerox.

“Basically anyone at Xerox can come up with a design idea,” says Polletto.

“Typically, the idea is presented to the person’s manager, who then evaluates whether Xerox should invest time and resources in furthering the idea.”

But even if the benefits are not obvious, Xerox doesn’t discourage the individual from refining the concept.

“The people behind the idea can form a team and develop the concept in their spare time, if they’re committed. Some of our people work on redesign ideas during lunch or after work.

“This is encouraged. Because sometimes, when you’re presenting things quickly, you may not be able to show all the benefits, or you may not be showing them in a way that is obvious.

“So someone who doesn’t receive management backing after the first proposal can continue developing a concept until it is ready to submit again.”

There are also established groups throughout Xerox that practice “skunk works,” says Polletto.

“One such group is field sales. They take existing products and try to re-engineer them for better serviceability and reliability, and lower cost.”

Areas of concern

The idea for the redesign of the roller/shaft assembly was good from the beginning and didn’t require much refinement, says Polletto.

There were areas, however, that were subjected to careful analysis, says Clyde Williams, senior project engineer.

“Lubricity of the bushings was something our plastics guys were very concerned with as they were evaluating materials,” says Williams.

But the key to the redesign was designing a way for the roller not to ride on the steel shaft, but in its own plastic bearings.

“We had to design features that would capture the shaft and channel dust away from areas where it tended to collect. “

Maytag’s Dependable Drive

Transmission redesign began nine years ago as a low-priority project. Today it’s a star. When one of Maytag’s research and development engineers stepped forward in early 1981 with an idea for simplifying the transmission in Maytag washers, the concept was put on the back burner.

Eventually, however, the idea resulted in Maytag’s Dependable Drive (TM) transmission, introduced last fall.

Maytag is so pleased with this redesign effort, it extended the transmission’s warranty from five years to 10 years. In the beginning …

So why was Maytag slow in moving forward with the redesign?

“In 1981, it was a matter of priorities,” says John Mellinger, vice president of research and development. “We were involved with developing our stacked washer and dryer.

“Plus we had a transmission out there for a lot of years (35 to be exact) that was doing an awfully good job. So we let the 1981 concept coast as a low-priority project, even though the concept showed a lot of potential.”

The concept called for converting the rotary motion of a single gear (the previous design had three gears) to the back-and-forth rocking of the agitator.

One of my engineers came to me with an 8-in.-high, 4-in.-wide, handmade wooden mockup, ” says Mellinger.

A working model was soon developed to prove the legitimacy of the principle.

But it wasn’t until 1983 that Maytag’s research and development engineers began working with the company’s manufacturing engineers on design evaluation. This work continued through 1984.

“As soon as we are seriously considering a design concept,” says Mellinger, “manufacturing engineering is in on the evaluation because they also have to speak to reliability and productibility issues before we go into production.” Black art

During the evaluation process it became evident that if the transmission redesign was to be successful, Maytag engineers would have to rethink another key component-the agitator.

The new agitator moves to and fro at 153 strokes a minute, as compared to the 64 strokes of the previous design. More strokes means there’s a greater chance that clothes may snag and tear, so the agitator was designed to be much smaller.

“We started out with a lot of agitator designs,” says Mellinger. “This is very much a black art. There aren’t exactly any textbooks on the subject. We spent a lot of time designing an agitator that would wash clothes very well without requiring more power so it could be used on all Maytag washers produced since 1956.” Task force formed

in early 1985, a multifunctional task force was formed to review the transmission for efficient manufacturability and reliability.

The group consisted of 12 persons representing research and development, manufacturing, design, marketing and finance, says Bob Faust, vice president of manufacturing.

“The transmission is the key element of our washing machine so we approached the redesign very cautiously,” says Faust.

Throughout the investigation phase, Maytag conducted extensive life tests on machines that house the new transmission.

“We were washing the equivalent of 10-lb. loads and were looking to accomplish a 10,000-machine cycle life (approximately 1,800 hours), the equivalent of a 20-year life,” says Faust.

While Faust and his manufacturing engineering group were conducting their tests, marketing was also evaluating product performance.

We manufacturing engineering) were looking at reliability of components,” says Faust. “Marketing was evaluating washability.”

Marketing was also concerned over the possibility of a negative reaction from our dealer network, says Mellinger.

“They (marketing) have their own product evaluation laboratory and spent much time evaluating whether a new agitator stroke and speed might scare away our retail customers.”

Meanwhile, Mellinger’s research and development group was busy investigating and evaluating materials, tooling and serviceability.

“We really took a good look at both reliability and washability,” says Mellinger.

One of the more important benefits we realized early on was that the entire transmission could be serviced from the front of the machine without removing the transmission.”

The redesign allowed all parts to be lifted out of the transmission by removing the front panel and transmission cover plate.

“Most gearcases require you to start at the top of the washer by taking off the tub and spinner, and working your way down before you can get the transmission in your hands to service it. This simplicity of service is one of the things we were quite enamored with early on,” says Mellinger Greatest DFM effort yet

When we formed the task force, we got very involved in design for manufacturing,” turing,” says Mellinger.

We evaluated die-cast gears, plastic gears, plastic components, castings. We evaluated a variety of different ways of manufacturing the few parts (40 as compared with 65 in the previous design) in the gearcase at the lowest cost possible without sacrificing quality.

“This project represents our greatest DFM cooperative effort between manufacturing and research and development in anything we’ve ever done. “