He’s Well-Armed, and Known as Robocop : Bears: Tight end James Thornton, from Cal State Fullerton, is a big man in Chicago.

Tight end James Thornton of the Chicago Bears sits quietly at his locker as wide receiver Glen Kozlowski, all 190 pounds of him, approaches and playfully assumes the pose of a bodybuilder. Fist clenched, arm raised, Kozlowski displays his 15-watt bulb of a biceps for all to see.

“Eh?” he says proudly. “What do you think of this?”

Actually, nobody thinks much of it at all, except Thornton, who glances sadly at the puny lump on his friend’s arm. Then again, about the only biceps bigger than the ones that bulge from Thornton’s shirt sleeves these days belong to his hero, Arnold Schwarzenegger, the man who has lifted more dumbbells than the academic adviser at the University of Oklahoma.

Thornton’s upper arms are the size of canned hams and as dense as a blacksmith’s anvil. Any bigger and he’d have to settle for a wardrobe of spandex.

These are the arms that have captivated a city, to say nothing of “Monday Night Football” announcer Dan Dierdorf, who breathlessly refers to Thornton’s prodigious iron pumpers as pipes.

And these are the arms that inspired Bear assistant coach Steve Kazor to promptly present Thornton with a nickname, Robocop, upon their meeting in 1988.

“I could think of a lot worse things that I could be called,” Thornton says.

An image was born that day, which was OK with Thornton, since he had spent the previous four years at Cal State Fullerton, a semi-obscure outpost to many National Football League scouts. In no time at all, this fourth-round draft pick became a local celebrity of sorts in a city that prides itself in making people larger than life.

William (the Refrigerator) Perry and Jim McMahon will vouch for that, as will Michael Jordan.

Now, if you need a judge for your aerobics contest, you call Thornton. Desire a spokesman for your charity effort? Thornton’s available. Need a guest on your television or radio talk show? Thornton will do it.

There is no children’s hospital too small, no dance contest too big that Thornton won’t consider. Bear public relations people marvel at his schedule, which occasionally numbers six appearances in seven days. He is easily the busiest Bear.

Last year, you could find him as a guest model in the Sears big-and-tall clothing catalogue. He does business luncheons. He graces golf tournaments with his presence. A Christmas ago, he became chairman of the Salvation Army’s local fund-raising campaign. If you asked him to stop by your 3-year-old daughter’s birthday party, Thornton probably would ask for directions.

He is seizing the day, he says, a quaint notion of youth that suffers a little more each time his phone rings. For instance, he soon plans to change his home phone number, thanks mainly to the volume of calls he receives. And Thornton can’t begin to count the number of requests he has had at speaking engagements when someone asks if he might remove his shirt.

“Everybody wants to see the arms,” he says.

To this, Thornton politely declines.

He is a cult figure all right, part fact, part fiction. But this much is for real:

--His arms, which have bench pressed an amazing--and team-high--575 pounds.

--His appeal. Soap opera star Noelle Beck, who appears in “Loving,” flew into town Friday to be with Thornton. That probably will be news to the Philadelphia Eagle cheerleader, whose photograph is taped to Thornton’s locker, or the Bloomingdale’s model, whose features also enjoy a prominent place on the locker wall.

--His playing ability, which, at the moment, says Kazor, is at the brink of Pro Bowl status. Without that, the coach reminds everyone, Thornton would be just another pretty face with mammoth arms.

“I think he’s going to be a reckoning force in the National Football League in the future,” Kazor says. “I think it’s unfortunate that we don’t throw the ball to the tight end as much as other teams do, or else he’d be a Pro Bowl prospect. In our mind, he is.”

Less than five years ago, Thornton didn’t even know the proper way to settle into a three-point stance. He became the personal project of Fullerton assistant Larry Manfull, who somehow turned an average quarterback into a functioning tight end. By his senior season, there was little doubt that Thornton would find a place in the NFL.

So impressive were his performances that year that one player, James Speer, a linebacker for the University of Florida, walked onto the Fullerton team bus after the Gators had beaten the Titans, 65-0. He found Thornton and said, “Hey, you’re the best tight end I’ve faced all year.”

At the scouting combine tryout camp at Indianapolis in 1988, Thornton tested better than Oklahoma’s highly regarded Keith Jackson in five of the seven categories. Jackson himself later told Thornton that he expected the Fullerton tight end to get drafted before he did.

Jackson was selected by the Philadelphia Eagles in the first round. Thornton went three rounds later.

Anyway, it was the thought that counted.

Thornton already has 17 receptions this season, which might not seem like a lot until you consider that only twice in the last six years has a Bear tight end caught 35 or more passes. Thornton should make it three in the last seven.

Also worth noticing is Thornton’s yards-per-catch average of 18.2, which is higher than the top 21 NFC receivers, except for San Francisco 49er Jerry Rice. In addition, Thornton leads the Bears in touchdown catches.

But no matter where he ranks in the weekly statistics, Thornton is best known for that science-fiction nickname and those arms of his. Until further notice, they have become his trademarks.

Earlier this year, Mel Franks, Fullerton’s sports information director, was in the Chicago area visiting friends. The conversation turned to football.

“So, have any of your players ever made it to the Bears?” asked one of the friends.

“Well, now that you mention it, there’s a guy there right now named Jim Thornton.”

“Really?” said the friend. “Never heard of him.”

“Plays tight end,” Franks said.

“Oh, you mean Robocop!”

And so it goes for Chicago’s newest curiosity piece. Adding to the mystique, of course, are those aforementioned biceps.

Every day, without fail, Thornton lifts weights. It is his hobby. Some say it his obsession.

In the garage of his Buffalo Grove (Ill.) home is a set of weights. In fact, it’s not uncommon for him to work out before he reports to the Bear practice facility each morning. Nor is it unusual, at least, for Thornton, to visit a gym immediately after practice for more weightlifting.

“When he’s bored, or something is bothering him, he goes out and lifts,” says his younger brother Gary, who plays at Fullerton.

Thornton will be available for viewing Sunday at Soldier Field, when the Rams play the Bears. And stare all you want, Thornton’s used to it.

“As long as they like me and I’m getting positive feedback, well, everybody knows me by my arms,” he says. “That’s not bad when a whole nation knows you, at least, for something. You stand out more than when you’re just wearing a number.”