所供拔除之患牙必须是不松动的。

The tooth requiring extraction must not be loose.

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本实用新型的有益效果是结构简单紧凑、拆装方便，不松动、经久耐用。

The utility model has the advantages of simple and compact structure and convenient assembly and disassembly and is not loosened and durable.

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适用于全自动装卸卷料的滑差轴，保证正反转时卷芯不移位，不松动。

Apply to differential slip shaft what full-automatic loading and unloading coil stock, ensure the volume do not shift and loose while counter rotating.

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