초록 ▼

A sports implement includes an electroactive element such as a piezoceramic sheet attached to the implement and a shunt circuit attached to the electroactive element to counteract strain or alter stiffness of the implement to affect its performance. In a ski, one shunt circuit is neither a linear no

A sports implement includes an electroactive element such as a piezoceramic sheet attached to the implement and a shunt circuit attached to the electroactive element to counteract strain or alter stiffness of the implement to affect its performance. In a ski, one shunt circuit is neither a linear nor a highly tuned shunt, but is a low Q resonant inductive shunt tuned to a performance band of the ski to enhance dissipation of energy from of the electroactive element. The performance band includes at least one structural mode of the ski and a neighborhood of that mode. The neighborhood may include variations in the frequency of a first or higher free structural resonance which arise from production variations or size variations of the ski or its components. The neighborhood may also be selected to cover the range of frequencies that mode takes when driven by actual disturbances in use, such as the vibrations excited when skiing at a particular range of speeds, or with a particular set of conditions or combination of conditions of temperature, speed, snow and terrain. In other embodiments, the tuned band shunt control may be switched to remove a resonance, adapt performance to different situations, or enhance handling or comfort of the implement. Other embodiments include striking implements intended to hit a ball or object in play, such as golf clubs and tennis racquets, wherein the strain elements may alter the performance, feel or comfort of the implement.

대표청구항 ▼

[ What is claimed is:] [1.] A ski comprisinga ski body;an electroactive assembly mounted on said ski body and including an electroactive sheet strain element for transducing electrical energy and mechanical strain energy, said electroactive assembly being coupled to said body in a region of strain,

[ What is claimed is:] [1.] A ski comprisinga ski body;an electroactive assembly mounted on said ski body and including an electroactive sheet strain element for transducing electrical energy and mechanical strain energy, said electroactive assembly being coupled to said body in a region of strain, anda control circuit comprising at least one band-limited circuit element and a switch, said control circuit being placed across said electroactive assembly and operative to preferentially alter dynamic response of said ski body to stimulation.