| 摘要 |
<p>A bowling alley bumper system which can be used for conventional bowling and for bumper bowling. The bowling alley bumper system includes a pair of gutters (30 and 32) having longitudinally extending portions (40 and 42) and extending and retracting means for moving those portions into an extended position to prevent a bowling ball from falling into a gutter and downwardly into a retracted position which allows bowling balls to fall into and roll along one of the gutters. Each of the longitudinally extending portions include an arc-shaped segment with first and second downwardly extending parallel projections. The longitudinally extending portions (40 and 42) lie on an x axis which is parallel with the major axis of the alley and which has a y axis laterally thereof and a z or vertical axis. The portions are moved upwardly or downwardly along an arc in an xz plane with little or no lateral movement.</p> |
