Open-celled stretchable putting surface and associated stretch measuring means

Claim 1

AS AN ARTICLE OF MANUFACTURE, A SYNTHETIC PUTTING GREEN, INTENDED TO APPROXIMATE CLOSELY ANY OF VARIOUS PUTTING SPEED CONDITIONS ENCOUNTERED ON AN ACTUAL GREEN, COMPRISING A GENERALLY FLAT, FLEXIBLE SHEET RESILENTLY STRETCHABLE IN ITS OWN PLANE IN AT LEAST ONE DIRECTION, WITH COMPLETE RECOVERY, TO THE EXTENT OF AT LEAST A 35% INCREASE IN ITS NORMAL DIMENSION AS MEASURED IN SAID DIRECTION, SAID SHEET BEING STRETCHABLE TO ANY OF A MULTIPLICITY OF SELECTED LENGTHS AND HAVING A PUTTING SURFACE OF OPENCELLULAR STRUCTURE PROVIDED WITH A TARGET AREA FOR A PUTTED GOLF BALL, THE CELLS OF SAID SURFACE OFFERING A FRICTIONAL RESISTANCE TO ROLLING MOVEMENT OF SAID BALL THEREUPON AND LENGTHENING IN SAID DIRECTION RESPONSIVE TO SELECTIVE STRECTCHING OF THE SHEET TO THEREBY LOWER SAID FRICTIONAL RESISTANCE IN CORRESPONDINGLY SELECTIVE FASHION; AND MEASURING MEANS AT LEAST A PORTION OF WHICH IS RETAINED AGAINST MOVEMENT IN RESPECT TO THE SHEET, SAID MEASURING MEANS PROJECTING BEYOND AN EDGE OF THE SHEET AND HAVING, ON ITS PROJECTING PORTION, INDICIA DENOTING VARIOUS DEGREES OF SAID FRICTIONAL RESISTANCE, SAID INDICIA BEING SELECTIVELY REGISTRABLE WITH SAID EDGE OF THE SHEET IN RESPONSE TO STRETCHING OF THE SHEET TO A CORRESPONDINGLY SELECTED EXTENT.