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NTIS 바로가기국가/구분 | United States(US) Patent 등록 |
---|---|
국제특허분류(IPC7판) |
|
출원번호 | US-0781120 (1977-03-25) |
발명자 / 주소 |
|
인용정보 | 피인용 횟수 : 11 인용 특허 : 0 |
A sports practice device for practicing the stroking motion used in games such as tennis, baseball, squash and the like includes a pair of guide rails mounted to the floor and ceiling of a room, a pair of carriages constrained to move relative to the rails between stops mounted in the rails, and a b
A tennis practice device, comprising first and second rigid guide rails mounted in parallel to upper and lower vertically spaced-apart support members respectively, first and second wheeled carriage means mounted respectively for movement along said first and second rigid guide rails, a ball, an ela
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