Method for calibrating a backlash impulse device in a sport implement

• US 7,886,572 B2
• Filed: 07/21/2008
• Issued: 02/15/2011
• Est. Priority Date: 02/23/2006
• Status: Expired due to Fees

• Current Assignee: Neil A. Harpham
• Original Assignee: Neil A. Harpham
• Inventors: Harpham, Neil A.
• Primary Examiner(s): Williams; Hezron
• Assistant Examiner(s): KOLB, NATHANIEL J
• Application Number:
  US12/219,338
• Publication Number:
  US 20080282768A1
• Time in Patent Office: 939 Days
• Field of Search: 73/110.1, 473/326
• US Class Current: 73/11.01
• CPC Class Codes: A63B 2053/0495 moving on impact, slidable, spring or otherwise elastically biased
• CPC Class Codes: A63B 53/0433 with special sole configurations
• CPC Class Codes: A63B 53/0437 with special crown configurations
• CPC Class Codes: A63B 53/0466 wood-type
• CPC Class Codes: A63B 60/50 with through-holes A63B60/18 takes precedence; for stringing purposes A63B49/00
• CPC Class Codes: A63B 60/52 with slits

Abstract

The calibration of a backlash impulse device in a sport implement (20) is effected by firstly measuring the natural frequency of the striking surface (26) of the implement; determining from the measured natural frequency, a time of occurrence *T* and a duration of a period of elastic recovery *R′ of the striking surface (26) in a first vibration cycle *P* following an impact on the striking surface (26). The method also comprises the step of adjusting a distance of travel ‘D’ of the movable mass (32) inside the backlash impulse device during a strike of a ball with the sport implement (20), such that an impulse (62) is generated on the striking surface (26) by this movable mass (32) during the strike, at the same time as the occurrence of the period of elastic recovery ‘R’ of the striking surface, in the first vibration cycle ‘P’ following the strike.

Claims

1. A method for calibrating the timing of a backlash impulse device in a sport implement having a striking surface and a movable mass mounted therein, comprising the steps of;

measuring the natural frequency of said striking surface of said implement;

determining from said natural frequency a time of occurrence and a duration of a period of elastic recovery of said striking surface in a first vibration cycle following an impact on said striking surface and relating a movement of said movable mass to said first vibration cycle;

adjusting a distance of travel of said movable mass during a strike of a ball with said sport implement such that an impulse generated by said movable mass during said strike occurs during said period of elastic recovery of said striking surface in said first vibration cycle;

wherein said movable mass comprises mercury enclosed in a cylindrical capsule and said step of adjusting a distance of travel is effected by selecting a single cylindrical capsule from a plurality of cylindrical capsules each having a same volume of mercury therein and a unique movable-mass travel distance, and mounting said single cylindrical capsule inside said implement; and

wherein said step of selecting is effected by extrapolation from two different vibration measurements of impulses on said striking surface, caused by two different ones of said cylindrical capsules alternately mounted in said implement, in two different experiments carried out at a same swing speed of said sport implement.

2. The method as claimed in claim 1, wherein said step of adjusting includes the step of adjusting a distance of travel of said movable mass during a strike of a ball with said sport implement such that an impulse generated by said movable mass during said strike occurs between the beginning and a mid-span of said period of elastic recovery.

3. The method as claimed in claim 1, further including a measurement of vibration in said implement confirming a properly calibrated cylindrical capsule.

4. A method for calibrating the timing of a backlash impulse device in a golf club having a movable mass mounted therein, comprising the steps of;

striking a striking surface of said golf club at a swing speed;

measuring the natural frequency of said striking surface;

determining from said natural frequency a time of occurrence and a duration of a period of elastic recovery of said striking surface during a first vibration cycle in said striking surface during said step of striking;

relating a movement of said movable mass during said step of striking to said first vibration cycle;

adjusting a time of travel of said movable mass following an impact on said golf club at said swing speed such that a kinetic energy of said movable mass is transferred to said striking surface during said period of elastic recovery of said striking surface during said first vibration cycle;

wherein said movable mass comprises mercury enclosed in a cylindrical capsule and said step of adjusting said time of travel is effected by selecting a single cylindrical capsule from a plurality of cylindrical capsules each having a same volume of mercury therein and a unique movable-mass travel distance.

5. The method as claimed in claim 4, wherein said step of adjusting is effected such that said kinetic energy of said movable mass is transferred to said striking surface between a beginning of said period of elastic recovery, and a mid-span along said period of elastic recovery.

6. A method for calibrating the timing of a backlash impulse device in a sport implement having a striking surface, comprising the steps of;

measuring the natural frequency of said striking surface of said sport implement;

determining from said natural frequency a time of occurrence and a duration of a period of elastic recovery of said striking surface in a first vibration cycle following an impact on said striking surface;

alternately mounting a first and second capsules in said sport implement, wherein each of said capsules contains a same movable mass and a unique movable-mass travel distance;

striking said striking surface at a same swing speed in first and second experiments with said first and second capsules respectively;

obtaining vibrations measurements of impulses on said striking surface from said movable mass in said two experiments;

selecting by extrapolation from said vibration measurements;

an unique capsule from a plurality of capsules each having said same movable mass therein and a different movable-mass travel distance, such that an impulse generated by said movable mass during a strike against said striking surface occurs during said period of elastic recovery of said striking surface in said first vibration cycle during said strike, and

mounting said unique capsule inside said implement.

7. The method as claimed in claim 6, further including a measurement of vibration in said implement confirming a properly calibrated capsule.