Method and apparatus for determining the performance of sports bats and similar equipment

A method of determining a performance of a first object comprising a known Moment of Inertia about a predetermined rotation point impacting a second object which has known characteristics including a known Coefficient of Restitution, the method comprising the steps of:

• (a) rotatably mounting the first object at the predetermined rotation point;
• (b) causing the first and second objects to have essentially non-spin impact so as to cause the first object to rotate and the second object to rebound after the impact;
• (c) measuring the velocity of the second object relative to the first object before the impact of the two objects;
• (d) measuring the velocity of the first object after impact with the second object;
• (e) determining the Coefficient of Restitution between the first and second objects using the measured velocities from steps (c) and (d);
• and
• (f) determining a performance factor for the first object from the known characteristics of the second object and the Coefficient of Restitution between the first and second objects.

A method of determining a performance of a first piece of sports equipment having a Moment of Inertia "I" about a predetermined axis of rotation thereof that is used to strike a second piece of sports equipment having a weight "w" and a predetermined Coefficient of Restitution comprising:

• (a) mounting the first piece of sports equipment at the predetermined axis of rotation thereof in a mounting means, the mounting means being arranged to allow the first piece of sports equipment to freely rotate from a stationary predetermined starting position when the first piece of sports equipment is impacted substantially normal to a longitudinal axis thereof and substantially at a center of a predetermined impact area thereof by the second piece of sports equipment;
• (b) causing the second piece of sports equipment to be propelled with a velocity "v" at the center of the predetermined impact area of the first piece of sports equipment;
• (c) measuring the velocity "v" of the second piece of sports equipment with a first measuring means;
• and
• (d) measuring the velocity "V" of the first piece of sports equipment with a second measuring means as the first piece of sports equipment rotates about its axis of rotation from being impacted by the second piece of sports equipment for determining a Coefficient of Restitution between the first piece of sports equipment and the second piece of sports equipment, and a performance factor of the first piece of sports equipment.

A system for determining a performance of a first object comprising a known Moment of Inertia impacting a second object which has known characteristics including a known Coefficient of Restitution, the system comprising:

• mounting means for rotatably mounting the first object such that the first object will rotate when the first and second objects impact each other;
• means for causing the second object to have a non-spinning impact with the first object so as to cause the first object to rotate and the second object to rebound after impact;
• first measuring means for measuring the velocity of the second object relative to the first object before the impact of the two objects;
• and
• second measuring means for measuring the velocity of the first object after impact with the second object so as to determine a performance factor for the first object.

A gas cannon for propelling an object placed therein comprising:

• a structure having sidewalls which define a bore having a cross-section that is selected so as to facilitate movement of the object through a portion thereof;
• a piston arranged for movement within the bore with a surface thereof having a contour shaped to cradle the object when the object is propelled out of the bore after being placed therein;
• accelerating means for causing the piston to be accelerated so as to cause the object to be cradled on the surface of the piston and propelled out of the bore without touching the sidewalls of the bore and with substantially no spin thereon;
• and
• decelerating means for subsequently causing the piston to be decelerated.