US Patent 4,751,921
United States Patent and Trademark Office
University of Iowa Research Foundation (Iowa City, IA, US)
A pair of screens in the barrel of a bone cement syringe improves the strength of the bone cement by breaking large bubbles into many small bubbles.
Park, Joon B. Bone cement syringe. US Patent 4,751,921 filed October 21, 1985 and issued June 21, 1988. https://ir.uiowa.edu/patents/60