Chubby Cox, a former University of San Francisco guard and three-year Continental league veteran with no National Basketball Association experience, was signed to a 10-day contract by the Washington Bullets yesterday, the latest candidate in their seemingly endless search for a shooting guard.

"We'll just take a look at him for 10 days. He's a good one-on-one player and that's what we need," said General Manager Bob Ferry.

"The point is we need help," added Coach Gene Shue. "Chubby is a good offensive player and I think he played well in practice today, considering it was his first time."

Ferry said he never considered bringing back Billy Ray Bates, signed as a free agent before the start of the season and then released when Kevin Grevey came off the injured list. Without elaborating, Ferry said Bates has more personal problems than the Bullets are prepared to deal with.

"There are some other players around, but most of them have already failed somewhere," said Shue. "Frank (Johnson) isn't ready to play, so we'll see what Chubby Cox can do. We have a lot of guards, but not the one guy who can give us consistent scoring night in and night out."

Cox, 6 feet 3, 190 and definitely not chubby, was the eighth-round draft choice of the Chicago Bulls in 1978. He played for Wilkes-Barre, Pa., and Philadelphia in the Continental Basketball Association and in the 1979-80 season, while with Pennsylvania, he was second in the CBA in scoring with a 29.2 average. Cox is primarily a jump shooter. He also teaches science in junior high school.

"I don't want to talk much about what I can do or anything like that," Cox said after his first workout. "I just want to play well and maybe then I'll have something to say. Besides, I'm still dizzy from running into his picks," he said, pointing at Rick Mahorn.

Shue said he isn't satisfied with the production from his shooting guards since it was learned six games ago that Don Collins had a stress fracture in his left foot and would be sidelined at least a month. Collins was put on the injured list yesterday to make room for Cox.

Grevey has been starting with Carlos Terry, with Charles Davis and Bryan Warrick relieving him. Grevey hasn't been making his shots, Terry and Warrick aren't scorers, and "Charles just isn't a guard," said Shue. "That's why we needed help."

Johnson will be examined today and the Bullets are hoping he will be able to begin practicing soon, but it is uncertain when he will be ready to be activated.

Rookie Dave Batton, who had a career-high 15 points against Cleveland Saturday, continued to work with the first unit ahead of Spencer Haywood, who has an eye injury . . . The Bullets will play the Detroit Pistons at the Silverdome Wednesday (WDCA-TV-20 at 8:05) and, after facing the Golden State Warriors at Capital Centre Friday, will go to Texas for two games, Saturday at San Antonio and the next Tuesday at Houston.