US Patent 11890517 Ball bat with one-piece multi-wall barrel portion

A ball bat, extending along a longitudinal axis. The bat includes a barrel portion, an end cap and a handle portion. The barrel portion is formed of a fiber composite material and 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 includes first and second distal region walls longitudinally extending from the central region. The central region walls and the distal region walls form a first inner barrel wall and an outer barrel wall, respectively. The barrel walls are spaced apart by a first separation. The first separation is unfilled and longitudinally extends over the central region and the first distal region wall. The end cap and the handle portion are coupled to the distal and proximal region, respectively.