The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 08, 2008
Filed:
Jan. 25, 2005
J. Dewayne Allen, Paragould, AR (US);
Richard P. Bishop, Fairfax Station, VA (US);
J. Dewayne Allen, Paragould, AR (US);
Richard P. Bishop, Fairfax Station, VA (US);
Allen Engineering Corporation, Paragould, AR (US);
Abstract
Methods and apparatus for screeding freshly placed concrete in which the acoustic impedance of the treating equipment is made substantially equal to the acoustic impedance of the concrete slab. Portions of the screed contacting the plastic concrete are matched to an acoustic impedance approximating the acoustic impedance of plastic concrete, promoting the energy transferred to the concrete. The acoustic matching material is fabricated from a material that has an acoustic impedance within 67% to 150% of the acoustic impedance of the concrete being finished. The acoustic matching material has an abrasion resistance of no greater than 150 measured using ASTM Method G-65 where steel is given a rating of 100. The preferred matching material comprises ultra-high molecular weight polyethylene (UHMWPE) plastic.