More than 500 inventors in Maryland, Virginia and the District of Columbia have joined the Society of American Inventors in an effort to assure affordable U.S. Patent Office fees.

The Society of American Inventors, a nonprofit organization with more than 12,000 members around the United States, is dedicated to serve the small inventor.

Senate bill S. 2326, an appropriation bill, would satisfy Patent Office requests for inventor fees. thorn in the side of inventors is Public Law 96-517, passed by Congress during the Carter administration, which calls for a patent maintenance fee to go into effect in October. The society is lobbying to get that law repealed.

Also objecting to the request for higher Patent Office fees is the patent, trademark & copyright law section of the Virginia State Bar, whose chairman, Harrison E. McCandlish, recently testified before a congressional committee looking into the matter.

Recent U.S. Patents granted to residents of Maryland, the District of Columbia and Virginia:

Maryland

Michael Carpenter of Laurel. Flotation mattress. Patent No. 4,325,152. 19 claims.

Phillis E. Wasson of Oxon Hill. Swivel spoon feeding device. Patent No. 4,325,187. 4 claims.

Jerome L. Wicks of Baltimore. Patio door and window guard system. Patent No. 4,325,203. 10 claims.

Peter Bauer of Germantown and Julian Lazrus of Bethesda. Washing apparatus. Patent No. 4,325,235. 26 claims.

Donald J. Pastine of Highland. Electrical augmentation of detonation wave. Patent No. 4,325,305. 15 claims.

Paul V. King of Joppatowne, et al. Blast suppressive shielding. Patent No. 4,325,309. 15 claims.

Joseph P. Sattler of Silver Spring, et al. Heterodyne indiciac refractometer. Patent No. 4,325.635. 12 claims.

Ramanathan Panayappan of Potomac and David L. Venezky of Alexandria. Method and composition for cleaning metal surfaces with a film-forming composition. Patent No. 4,325,744. 7 claims. District of Columbia

Almet Mozbey. Derriere exerciser. Patent No. 4,325,379. 12 claims.

Walter T. Charlton. Solar power building block. Patent No. 4,326,012. 11 claims.

Virginia

Max N. Yoder of Falls Church. Simplified fabrication method for high-performance jet. Patent No. 4,325,181. 8 claims.

John E. Comparetto of Chincoteague. Solar heating apparatus. Patent No. 4,325,358. 20 claims.

Clemens A. Iten of Staunton and David O. Chase of Skaneateles, N.Y. Facial brush for controlling pseudofolliculitis barbae. Patent No. 4,325,392. 10 claims.

Robert A. Lofquist of Richmond. Method to reduce pressure drop in polyamide process piping. Patent No. 4,325,397. 3 claims.

Gordon G. Miller Jr. of Richmond. Battery cleaning apparatus. Patent No. 4,325,415. 13 claims.

William C. Butt of Lynchburg. Conveyor support way. Patent No. 4,325. Patent No. 4,325,480. 19 claims.

Glen E. Swinney of Axton. Painter's belt-on brush and buckle holder and carrier. Patent No. 4,325,503. 5 claims.

John R. McLean of Richmond. Sheet material dispensing mechanism. Patent No. 4,325,519. 4 claims.

Robert L. Brooke of Woodbridge. High-speed bulk-grain moisture measurement apparatus. Patent No. 4,326,163. 9 claims.

David L. Bergeron of Manassas. Structure and process for optimizing the characteristics of 12L devices. Patent No. 4,326,212. 2 claims.

Arthur P. Given of Roanoke and Michael F. O'Meara of Fes-sur-Mere, France. Method and apparatus for controlling a plurality of like equipment. Patent No. 4,326,263. 9 claims.