Avoidance of resonance in the inflatable sport ball by limiting the critical ratio

• US 20050124445A1
• Filed: 12/15/2004
• Published: 06/09/2005
• Est. Priority Date: 10/14/1999
• Status: Abandoned Application

• Current Assignee: Russell Asset Management, Inc. (Berkshire Hathaway Incorporated)
• Original Assignee: Russell Asset Management, Inc. (Berkshire Hathaway Incorporated)
• Inventors: LaLiberty, Ronald P., Veilleux, Thomas A.
• Application Number:
  US11/014,484
• Publication Number:
  US 20050124445A1
• Time in Patent Office: Days
• US Class Current: 473/593
• CPC Class Codes: A63B 2041/005 with counterweight for adjusting the centre of gravity
• CPC Class Codes: A63B 41/00 Hollow inflatable balls
• CPC Class Codes: A63B 41/12 Tools or devices for blowing up or closing balls for pricking-balls A63B39/04
• CPC Class Codes: F04B 33/00 Pumps actuated by muscle power, e.g. for inflating
• CPC Class Codes: F16K 15/147 the closure elements having specially formed slits or being of an elongated easily collapsible form
• CPC Class Codes: F16K 15/202 and with flexible valve member

Abstract

A sport ball having an internal device such as an internal pump has a critical ratio that insures that rebound characteristics or coefficient of restitution of the ball, such as a basketball, will be acceptable for use. The invention also includes the method for evaluating design and/or quality control of a sport ball by measuring the internal vibration and determining the critical ratio of the sport ball.

Claims

1. A ball comprising:

a carcass having at least one layer of material, the carcass defining an exterior surface and a generally hollow interior;

a device having an top and a bottom, wherein the device extends into the generally hollow interior of the carcass; and

a housing having an upper end with a flange extending therefrom and a lower end, the housing defining a central opening extending between the upper end and lower end of the housing, wherein the device is received by the central opening of the housing and extends therefrom, wherein the flange is coupled to the at least one layer of material and the lower end is disposed within the hollow interior of the carcass, and wherein the natural frequency of oscillation of the housing with the device coupled thereto is not in resonance with a predetermined loading force such that the performance characteristics of the ball are within an allowable range from specified performance characteristics for a second ball, the second ball defining a second housing that does not include a second device therein.

2. The ball of claim 1, wherein the housing defines a groove circumscribing the housing.

3. The ball of claim 1, wherein the ball is a basketball having a coefficient of restitution in the range of 0.750 to 0.813.

4. The ball of claim 3, wherein the ball has multiple values for the coefficient of restitution, and wherein the difference between the largest and smallest values of coefficient of restitution for the ball is equal to or less than 0.051.

5. The ball of claim 4, wherein the ball has multiple values for the coefficient of restitution, and wherein the difference between the largest and smallest values of coefficient of restitution for the ball is equal to or less than 0.036.

12. The method of claim 11, wherein the change in the housing involves a change in at least one of the flex modulus, bulk modulus, tension modulus, and compression modulus of the housing.

6. A method of testing a hollow ball, the method comprising the steps of:

providing a carcass, the carcass defining an exterior surface and a generally hollow interior, wherein the carcass includes at least one layer of material;

providing a device;

coupling the device to the at least one layer of material, wherein the device extends generally inward from the one layer of material and is substantially disposed into the generally hollow interior; and

providing a loading force that deforms at least a portion of the ball; and

determining whether the device oscillates at a frequency that is in resonance with the loading force.

7. The method of claim 6, further including the steps of:

responsive to determining whether the device oscillates at a frequency that is in resonance, altering the natural frequency of oscillation of the device.

8. The method of claim 7, wherein the natural frequency of oscillation of the device is altered by changing the mass of the device.

9. The method of claim 7, wherein the natural frequency of oscillation of the device is altered by changing the distribution of the mass of the device.

10. The method of claim 7, wherein the natural frequency of oscillation of the device is altered by changing the coupling of the device to the at least one layer of material.

11. The method of claim 7, wherein device is coupled to the at least one layer using a housing having the device extending therethrough, wherein the coupling is altered by changing the housing.