Robert H. Davis, a Washington lawyer whose avocation is collecting and selling comic books and antique pinball machines, was convicted of co-caine and marijuana offenses yesterday and sentenced to a seven-year prison term.

Before sentencing the 32-year-old Davis, U.S. District Court Judge William B. Jones criticized his actions in unusually strong terms, saying that narcotics make "cheap money for people who don't want to work."

"Now it's bad enough that some underprivileged person gets into it," Jones said. "But here is a man who went to law school in Boston (Suffolk University)... a member of the bar of this court for several years... And what does he do? He goes out and he gets involved in this dirty business and starts peddling this stuff."

Jones said the evidence in the case showed that Davis had sold the cocaine only to one other man, George Gelestino, a 26-year-old carpenter who also was convicted of cocaine offenses yesterday and sentenced to a three-year prison term.

But the judge said "there was just too much cocaine in that house [Davis' former residence at 5900 Moreland St. NW] to believe that he was going to use it for himself or his girlfriend and himself."

"A lawyer should never violate the law," Jones told Davis. "He takes an oath of office to uphold the law. You have seen fit, however, to disregard your oath; you've seen fit to disregard the law."

Assistant U.S. Attorney Joseph F. McSorley had agreed with Davis' defense attorney, Fred R. Joseph, to allow Davis to remain free pending an appeal on grounds that the search of Davis' house by D.C. police was illegal.

But Jones said he was not bound by that agreement, and ordered Davis jailed immediately. "This court is of the opinion that this man being in the narcotics business poses a danger to other persons and the community," Jones said.

Davis, who recently his lived at 3727 Kanawha St. NW, was arrested last March 23 after police raided his former residence. Police said they found about three ounces of highquality cocaine with a street value of about $50,000, as well as marijuana, peyote and hashish.

When police questioned him about the purity of the cocaine, they said Davis replied, "Well, let's put it this way. I'm a businessman and I sell nothing but the best."

Davis was convicted of possession of cocaine with intent to distribute it, and possession of marijuana. Gelestino, of 1848 Columbia Rd. NW, was convicted of conspiracy to distribute cocaine and three counts of unlawful distribution of cocaine. Davis' girlfriend, Frances A. Sinkovic, 29, also of the Kanawha Street address, was convicted of possession of cocaine and marijuana and fined a total of $1,000. The government dropped other drug charges against Davis and Sinkovic, McSorley said.