The Washington Capitals yesterday signed a big man with a big name to fill their goaltending vacancy.

Gary Smith, 6-foot-4 and 215 pounds, will plug the hole created by Ron Low's defection to Detroit. Smith became a free agent when his contract with Minnesota expired and, unlike Low's pact, no compensation is required. Accordingly, the Capitals' investment was a modest one, a one-year contract plus option.

Smith, 33, has played for Toronto, California, Chicago, Vancouver and Montreal in a lengthy NHL vareer marked by some brilliant goaltending and frequent expressions of personal dissatisfaction.

In 1970-71, with California, Smith played 71 games, then a league record, and would have played the entire schedule except for a skull fracture suffered when a shot by Philadelphia's Leon Rochefort rocked his mask.

In 1971-72, Smith posted a 2.41 goals-against average at Chicago and shared the Vezina Trophy with Tony Esposito. In 1974-75, his 3.09 average was an important factor in Vancouver's first-place finish in the Smythe Division.

Smith left California and Minnesota, however, because he wanted more money than those clubs offered. At Chicago, he complained because he wasn't playing enough. In his last year in Vancouver, he asked to be traded and groused enough to be suspended by coach Phil Maloney.

Swapped to Minnesota for another unhappy soul, Cesare Maniago, Smith spent more time plotting his future than playing. He was benched and told to lose weight, then played only twice in the last five weeks as Pete LoPresti carried the North Stars into the Stanley Cup playoffs.

"I admire Gary Smith and like him" Maloney said. "I only wish he liked his job well enough to play for us."

"I was under the impression Smitty was looking for another team all last year." said Minnesota coach Ted Hrris. "He negotiated with just about everybody. When guys don't want to play in a city, you can't do much about it, can you?"

Whether Smith will be happy in Washington is conjectural. It is known that he preferred to play on the West Coast. Also, he said last spring that "my major concern right now is the security of my family.I'm 33 now and the next contract I sign will probably be my last."

That sound like the words of a man who was expecting a longer term than the one year the Capitals gave him.

Washington general manager Max McNab was undeterred by Smith's history of discontent.

"We think we're making a good move," McNab said. "Even before the Low thing we wanted Gary in our organization. He has the experience, the record, puck-handling ability and size.

"We're not concerned about his past problems. We've discussed these things. His atitude doesn't faze us. He's got the playoff experience. I know it's 'that' division, but he's been through the first-place pressure in Chicago and Vancouver."