US Patent 4,130,283
United States Patent and Trademark Office
University of Iowa Research Foundation (Iowa City, IA, US)
A device for use in connection with a golf game or practice apparatus for simulating a fairway surface to enable a player to execute each shot as he would in actual play, especially enabling the player to "strike down" at the golf ball with the simulated feel of taking a chunk of turf but without damaging the simulated fairway surface. The device utilizes an artificial grass turf secured to a cushioned support that is movable in the direction of flight of the ball and compressible when the surface is struck during the golfer's swing. The movable and compressible portion of the artificial turf will return to its original position as soon as the club head is disengaged from the turf. The movable section of artificial turf together with the cushioned support thus provides the golfer with the same "feel" as if actual turf had been taken during the golf shot.
Lindquist, Everet F. Simulated fairway surface for golf apparatus. US Patent 4,130,283 filed January 06, 1977 and issued December 19, 1978. https://ir.uiowa.edu/patents/13