公开(公告)号：US3807213A

公开(公告)日：1974-04-30

申请号：US24978572

申请日：1972-05-03

Applicant: ALUMINUM CO OF AMERICA

Inventor： WILLIS E ,  NELSON D

IPC: A63B59/06 ,  B21D53/00 ,  B21D51/16

CPC classification number: B21D53/00 ,  A63B59/50 ,  A63B2102/18

Abstract: A hollow metal ball bat and method of making the same. The bat is formed from a unitary metal tube having a completely open end at one end thereof and a partially or completely closed, integral end wall at the other end thereof. A portion of the tube including the open end thereof is reformed to provide the portion with a reduced wall thickness which, in turn, is reduced in diameter to form the handle portion of the bat. An intermediate portion of the tube tapers between the handle portion and a barrel portion having the diameter of the original tube and the closed end wall. The reduction in diameter increases the thickness of the wall of the handle portion to a thickness approximating that of the barrel portion of the bat so that the ratio of the weight per unit length of the handle and barrel portions thereof is substantially the same as the ratio of their diameters.

Abstract translation: 一种中空金属球棒及其制作方法。 蝙蝠由其一端具有完全开口端的单一金属管和在其另一端处的部分或完全封闭的整体端壁形成。 包括其开口端的管的一部分被重新形成以使该部分具有减小的壁厚，该厚度又减小直径以形成蝙蝠的手柄部分。 管的中间部分在手柄部分和具有原始管的直径和封闭端壁的筒部分之间变细。 直径的减小将手柄部分的壁的厚度增加到接近蝙蝠的圆筒部分的厚度，使得手柄和其圆筒部分的每单位长度的重量比例与该比例的比率基本相同 的直径。