"Patience is a virtue," goes the old adage.

And Mark Legenstein is nothing if not patient.

Determined, too.

Five-plus years after introducing his Knee Blades at a Baltimore trade show, he finally has gotten them on a major retailer's shelves.

Knee Blades — shock-absorbent kneepads on rollers — are now available at 300 of Lowe's 1,720 home-improvement stores nationwide.

Those include its store at 25 Rohrerstown Road but not its 1845 Hempstead Road location.

Seeing his Knee Blades on the local store's shelves at last was an emotional moment for the persistent inventor.

"It was awesome," Legenstein said.

Legenstein, 32, of Lancaster Township, received his first Knee Blades patent in 1999, but spent years perfecting them before going to the October 2005 trade show.

Still, his breakthrough didn't occur until he went to another trade show in 2008 and met a Texas firm that supplied Lowe's.

That was a huge relief for the married father of three, who's also vice president of the flooring division for the family business, Certified Carpet Inc.

It was Legenstein's experience as a Certified Carpet vinyl flooring installer, a job that requires a person to be constantly on his knees, that gave him the idea for Knee Blades.

"There had to be a better way" than putting repetitive pressure on that sensitive joint, he said.

So Legenstein created Knee Blades.

His first version, assembled in the family garage, was simply a pair of kneepads bolted to furniture-moving casters.

The current version is far more sophisticated.

The product, priced at $59.98 a pair, has a hard-plastic black kneepad with a gel insert.

The kneepad is mounted on a mustard-yellow triangular base with three Neoprene wheels.

An adjustable strap secures it to the back of the knee; the kneepad portion can be disconnected from the rest with a push button if someone wants to use only that.

The Neoprene wheels don't leave marks on floors, said Legenstein, president and founder of Knee Blades LLC.

He said Knee Blades aren't just ideal for carpet installers, but for employees who work in the automotive, painting, plumbing and electrical trades, and even those in the airplane manufacturing industry.

Do-it-yourselfers will like them, too, Legenstein said.

"The mobility on a job is second to none," he said.

In fact, the tagline on the product's box is "You Kneel, You Glide."

Knee Blades also are very durable, Legenstein said. The listed weight limit is 300 pounds, "but that might not even break it," he said.

When he takes Knee Blades to trade shows, they're always a big hit, Legenstein said.

At the 2005 Baltimore Remodeling Show, he received the Best New Product of the Year award.

In 2008, Legenstein earned the Most Outstanding & Innovative Product Award at the National Hardware Show in Las Vegas, while his invention was given a Retailers' Choice Award.

Because Knee Blades have been modified some since he got his first patent, Legenstein was issued a second patent in March of last year.

He also said a Canadian patent, which he hopes to receive within the next two years, is pending.

"It's a terribly expensive process," he said, potentially costing tens of thousands of dollars.

Legenstein said he originally tried to sell Knee Blades online, but "that wasn't really working."

And for a while, "I couldn't connect with anybody to take it retail," he said.

That changed when a buyer from Lowe's put Legenstein in touch with The Rooster Group, with headquarters in San Antonio, at the 2008 National Hardware Show.

"Rooster is so huge, I put it in their hands," Legenstein said, allowing him to devote more time to his day job.

His licensing agreement means The Rooster Group will manufacture, promote and distribute Knee Blades while Legenstein will receive a royalty from sales.

First produced in Rochester, N.Y., Knee Blades are now made in China, he said.

The sale price also has dropped significantly from the $169.99 it was in 2005.

Legenstein said companies have to meet "mega standards" to sell their products at Lowe's, including documenting that the factory where Knee Blades are made "is not a sweatshop."

The 300 stores that carry Knee Blades are spread all over the U.S., he said.

This is only a test run, and distribution could go much wider, including into Canada and Mexico, Legenstein said.

"It's hard to get into a store like Lowe's," he said.

Legenstein also envisions the product being sold in such automotive supply stores as AutoZone, Pep Boys and Advanced Auto Parts.

But it will be hard to top the thrill of getting Knee Blades into a local Lowe's.

When he found out approximately when they were going to debut, Legenstein went to the store several days in a row to look for his product.

Finally they appeared Dec. 19, the Sunday before Christmas.

Seeing them stacked in the kneepad section by Tool World was an unbelievable moment, Legenstein said.

Legenstein called his dad, Walt, and brothers Steve and Joe, who came over to snap pictures of him and the Knee Blades display.

Later on, he said, the whole family plans to mark the milestone with a celebratory dinner.

Paula Wolf is a staff writer for the Sunday News. She can be reached by e-mail at pwolf@lnpnews.com.