Active Control Experts, Inc.

Jonathan C Allen

Robert N Jacques

Kenneth B Lazarus

Jeffrey W Moore

Emanuele Bianchini

Farla M Russo

Carl Prestia

Ronald Spangler

David Gilbert

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 recreational board such as a snowboard incorporates strain transducers to damp a plate resonance of the board. The strain transducers are preferably located around a peripheral region to capture strain energy affecting control edges, for example steering control edges at the front and/or rear of the board. Electrical energy from the transducers is shunted to damp a targeted resonance. In a preferred embodiment the strain transducers cover a region of the snowboard adjacent one surface and extending along the forward periphery, preferably at both inside and outside edges, and are shunted with a resonant shunt tuned to a torsional or torsion-like mode of the board that is excited during steering maneuvers. The transducers may be fabricated as preassembled sheets or may be formed in the snowboard during the assembly process using sheets of piezoceramic material, or using piezo fiber or other composite constructions. The strain material may be positioned to preferentially shift or damp one resonance mode, and/or it may be arranged to exert a directional effect or anisotropic control authority. A passively operated embodiment employs a simple resistive shunt to enhance control of strain energy at the frequency of a resonant mode of the snowboard. Damping of that mode reduces chatter of the steering edges in use. The strain elements may be used in conjunction with viscoelastic or other damping mechanisms to tailor the overall level of mechanical control and limit the allowed excitations of the board.

Recreational snowboard

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

A sports implement including 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 golf clubs and tennis racquets, wherein the strain elements may alter the performance, feel or comfort of the implement.

Adaptive sports implement

Cutting board for fish

Growing community of inventors

Brookline, MA, United States of America

Jonathan C Allen