| 摘要 |
<p>The barrel has a biconical grip located partially in a main body i.e. sheath, to tighten and/or loosen a material i.e. bar. A single-piece piston (105) is located partially in the body to pneumatically tighten and/or loosen the material. The piston has a base (202) and a separation wall (204) extending radially from the base. The wall transversely separates chambers located axially in the barrel with respect to a longitudinal axis of the barrel. The wall comprises a shape of lobes (201), so that radial thickness of the wall, in a plane perpendicular relative to the axis, is not constant. The lobes have round, square or triangular shape.</p> |
