Active Control Experts, Inc.

Carl Prestia

Kenneth B Lazarus

Jeffrey W Moore

Robert N Jacques

Farla M Russo

Emanuele Bianchini

Jonathan C Allen

Ronald Spangler

David Gilbert

Edward F Crawley

Erik Saarmaa

Eric Fitch

A golf club includes an electroactive assembly attached to the club and electrically tuned to capture energy from one or more vibrational modes with high efficiency. More generally, a sports implement includes an electroactive element, such as a piezoceramic sheet attached to the implement, and a circuit attached to the electroactive element. The circuit may be a shunt, or may include processing such as amplification and phase control to apply a driving signal which may compensate for strain sensed in the implement, or may simply alter the stiffness to affect performance. The electroactive element is located in a region of high strain to apply damping, and may include plural subassemblies mounted to capture energy in different planes, or to capture an asymmetric strain distribution while maintaining structural symmetry. In a ski the element captures between about one and five percent of the strain energy of the ski. The region of high strain may be found by modeling mechanics of the sports implement, or may be located by empirically mapping the strain distribution which occurs during use of the implement. In other embodiments, the electroactive elements may remove resonances, 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 mallets, bats and tennis racquets, wherein the strain elements may alter the performance, feel or comfort of the implement. The electroactive elements may be configured in sets to capture energy in different modes, and/or energy distributed along different directions.

Sports implement

A hybrid actuator includes strain actuated elements that displace fluid to move a piston, with the elements forming a fluid housing, and being oriented and actuated to optimize force, stroke or bandwidth. In one preferred embodiment the elements are cylinders enclosing the fluid, with radial and axial components of strain-induced dimensional change adding together to enhance displacement. In another preferred embodiment, piezo bender elements produce large stroke, high bandwidth movements. Strokes of up to fifty percent of actuator length, and bandwidths above 500 Hz are achieved in light weight electrically actuated devices free of external piping or hydraulics. The actuator is readily integrated into a gate valve, sub-woofer, or other driven device.

High bandwidth, large stroke actuator

Golf club

A baseball bat includes an electroactive assembly attached near the handle and electrically tuned to capture energy from several modes with high efficiency. More generally, a sports implement includes an electroactive element, such as a piezoceramic sheet attached to the implement, and a circuit attached to the electroactive element. The circuit may be a shunt, or may include processing such as amplification and phase control to apply a driving signal which may compensate for strain sensed in the implement, or may simply alter the stiffness to affect performance. In a ski, the electroactive element is located near to the root in a region of high strain to apply damping, and the element captures between about one and five percent of the strain energy of the ski. The region of high strain may be found by modeling mechanics of the sports implement, or may be located by empirically mapping the strain distribution which occurs during use of the implement. In other embodiments, the electroactive elements may remove resonances, 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 mallets, golf clubs and tennis racquets, wherein the strain elements may alter the performance, feel or comfort of the implement. The electroactive elements may be configured in sets to capture energy in different modes, and/or along different directions.

Baseball hat

Growing community of inventors

Stow, MA, United States of America

Carl Prestia