| 摘要 |
A sports racket such as a tennis racket has a head comprising a pair of concentric frames wherein an inner frame equipped with tensioned strings is supported resiliently within an outer frame by an inflated tube lying within opposing parallel channels extending respectively about the periphery of the inner frame and along the interior of the outer frame. Variation of the pressure of inflation of the tube controls the elasticity of the support of the inner frame, and deflation of the tube permits rapid removal and replacement of the inner frame.
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