BACKGROUND

Baseball and softball bats are well known sporting goods. The materials used to form bats have changed and become more varied overtime, including materials such as wood, aluminum, other alloys, fiber composite materials and combinations thereof. Additionally, the construction of ball bats has also evolved and become more varied overtime. The cost of many existing bat constructions can be very high due to the complexity of the construction, the cost of the materials, and the time required to produce the finished ball bat.

Accordingly, a need exists for bat configurations that provide exceptional performance, durability and reliability characteristics without excessive material and/or manufacturing costs. It would be desirable to provide a bat construction and method of manufacturing that is cost effective, allows for shorter production lead times and exceptional performance. A need exists for a ball bat that provides exceptional feel to the player, even upon off center impacts with the ball.

SUMMARY OF THE INVENTION

The present invention provides a ball bat extending along a longitudinal axis and configured for impacting a ball. The bat includes a barrel portion, an end cap and a handle portion. The barrel portion includes a proximal region having a continuous single wall construction, a central region and a distal region. The central region includes at least first and second central region walls longitudinally extending from the proximal region, and a distal region including first and second distal region walls longitudinally extending from the central region. The first and second central region walls and the first and second distal region walls form a first inner barrel wall and an outer barrel wall, respectively. The first inner barrel wall and the outer barrel wall are spaced apart by a first separation. The first separation is unfilled and longitudinally extends over the entire length of the first distal region wall and at least a portion of the length of the central region. An end cap is coupled to the distal region of the barrel portion. A handle portion is coupled to the proximal region of the barrel portion.

According to a principal aspect of a preferred form of the invention, a method of forming a ball bat extending along a longitudinal axis and configured for impacting a ball is provided. The method includes obtaining a mandrel shaped to define at least an inner surface of a barrel portion of the bat, and wrapping a first plurality of layers of fiber composite material about the mandrel. The first plurality of layers of fiber composite material is initially uncured. The mandrel extends along the longitudinal axis. The first plurality of layers wrapped about the mandrel have a first longitudinal dimension. The method further includes placing a removable material over a first portion of the first plurality of layers. The first portion of the first plurality of layers covered by the removable material has a second longitudinal dimension that is less than the first longitudinal dimension. The method further includes wrapping a second plurality of layers of fiber composite material over the removable material covering the first portion of the first plurality of layers and over at least a second portion of the first plurality of fibers. The second portion of the first plurality of fibers is uncovered by the removable material. The second plurality of layers of fiber composite material is initially uncured. The first and second plurality of layers and the removable material form a pre-molded barrel portion lay-up. The method further includes separating the mandrel from the pre-molded barrel portion lay-up, inserting an expandable member within the pre-molded barrel portion lay-up, inserting the pre-molded barrel portion lay-up into a barrel-forming mold, and molding the first and second pluralities of layers together with the removable material in a single molding cycle. The method then provides for curing the first and second pluralities of layers with the removable material to form at least the barrel portion of the bat, and removing the removable material and the expandable member from the barrel portion,

This invention will become more fully understood from the following detailed description, taken in conjunction with the accompanying drawings described herein below, and wherein like reference numerals refer to like parts.

