Used to be, Joe Wheelwright didn't have to account for his time to anyone. He was a full-time sculptor.

"If I wanted to spend the day polishing a piece of stone or cleaning a moose skull . . . well, it didn't matter much," Wheelwright said, sounding a little wistful. "As long as I produced enough work to feed my family, of course. Generally, my time was my own."Now, time is the enemy. I'm a businessman. There's always a schedule to keep in mind, somewhere I need to be."

Wheelwright's world began to evolve from shaping-up to shipping-out on Easter morning 1980, when he decided to invent a better roller skate.

"While I was stalled in a traffic jam, I watched people skating on the Esplanade near the Charles River," recalled Wheelwright, who lives in Boston. "I envied the liberated feeling that the sport provided, but to an artist the skates and their little wheels seemed ludicrous.

"I wondered why there couldn't be a wheeled platform that would enable a person to glide much easier, a skate that would be safer and which would have some kind of brake."

Two days later, Wheelwright completed a prototype of what is now known commercially as - what else? - the Wheel Right Skate.

Wheelwright's Wheel Rights consist of two saucer-size wheels in back and a silver-dollar-size wheel at the point. A plastic-tipped bar that extends from the heel serves as a brake and keeps wearers from toppling backward.

The skates, which retail for $200 a pair, are the result of eight years of development.

"This is the first major change in skates since they were invented a century ago to give women a socially acceptable means of exercising," Wheelwright said. "Men never skated then. They just watched."