Abstract: A golf swing practice mat for placement on an underlying base is provided to aid a golfer in improving his or her swing of a golf club having a club head, said swing comprising a swing arc having a bottom-most portion thereof, said golf swing practice mat comprising: (a) a low friction, flexible and resilient top sheet that is directly contacted by the club head, and has a rigidity of 40 pounds per square inch or less; (b) a supporting pad for supporting the top sheet and for providing space for the top sheet to yield to and accommodate the bottom-most portion of a reasonably well-aligned swing arc, the supporting pad being compressible to 50% of its resting height in any area near its center line by an applied pressure thereupon of 0.

Abstract: A golf swing practice mat for placement on an underlying base is provided to aid a golfer in improving his or her swing of a golf club having a club head, said swing comprising a swing arc having a bottom-most portion thereof, said golf swing practice mat comprising: (a) a low friction, flexible and resilient top sheet that is directly contacted by the club head, and has a rigidity of 40 pounds per square inch or less; (b) a supporting pad for supporting the top sheet and for providing space for the top sheet to yield to and accommodate the bottom-most portion of a reasonably well-aligned swing arc, the supporting pad being compressible to 50% of its resting height in any area near its center line by an applied pressure thereupon of 0.

Abstract: A user-friendly golf swing practice mat is provided, comprising: (a) a low friction, compliant and resilient top sheet having a rigidity of less than 40 pounds per square inch; and (b) a bottom pad (natural grass or an accompanying compliant, resilient pad) for supporting the top sheet a finite distance above the underlying base, for providing space for the top sheet to yield to and accommodate the bottom-most portion of a reasonably well-aligned golf club swing-arc. The golf swing practice mat avoids the mechanical limitations and problems associated with prior art mats. In typical usage, the respective properties of the top sheet and the bottom pad together enable the whole mat to function so that--like a natural-grass-covered fairway--it imposes very little resistance as it readily yields to and accommodates the bottom-most portion--between the bottom of the ball and the underlying ground/base--of any fill, and reasonably well aligned golf club swing arc.

Abstract: Pre-ski testing and exercising apparatus comprising a pair of elongated members which may be actual or simulated skis, and which are clamped by appropriate clamping devices to a pair of rigid cross bars, each of which is supported by a pair of rocker blocks. The apparatus allows the user forceably to rock the skis, or simulated skis, forward or backwards, or from side-to-side. Also, one of the cross bars, usually the rear cross bar, may be positioned relatively higher on its rocker blocks than the forward cross bar so as to tilt the skis, or simulated skis slightly forward, even while at rest. The apparatus of the invention prevents the skis, or simulated skis, from rotating freely about their longitudinal axis, and from moving freely independently of one another.

Abstract: Apparatus is provided for measuring the ability of an athlete to jump vertically from a standing or running position. Such apparatus is useful, for example, in enabling coaches to determine the ability of athletes for such sports as basketball, volleyball, and even competitive swimming. The apparatus includes an upright frame which can be positioned away from any wall or other structure which could interfere with the use of the apparatus. A series of horizontally extending vanes are pivotally mounted one above the other in spaced parallel relationship at the upper end of the frame for individual angular movement about a vertical axis. The vanes are retained in their uniformly spaced and parallel relationship by, for example, a stack of precision spacers, or accurately spaced retaining rings, and axial-loading spring washers, or coil springs. The vanes are mounted so that they may pivot freely about the vertical axis on an individual basis, independent of all the other vanes.