Blocking machine comprising pivotally mounted, spring-biased blocking arm
作者： Mel W Thompson
DOI:
关键词: Optoelectronics 、 Spring (mathematics) 、 Blocking (radio) 、 Computer science
摘要:
lens.org 参考文章(2)
Charles P Forrest, Multi-purpose wheeled football training apparatus ,(1965)
John B Noftsinger, Football blocking machine ,(1952)