| 摘要 |
The invention relates to gripping means for use in the withdrawal of tubular members such as heat exchanger tubes from support means. The gripping means comprises an expandible collet arrangement adapted to be received within the tubular member, a main body portion having an end portion adapted to bear against the support means, a piston device slidably received in said body portion and defining at least one wall of an annular chamber within the body portion, a draw bar secured to the piston said draw bar having a head portion having a larger diameter than that of the draw bar, said draw bar passing concentrically through the body portion and the collet arrangement so that the head portion of the draw bar normally protrudes beyond said collet arrangement, the construction being such that on the introduction of pressurizing fluid into said annular chamber the draw bar is withdrawn into the body portion, the collet arrangement being forced to expand in diameter by the entry of the bar head portion, until the collet arrangement grips the internal surface of the tubular member, continued withdrawing movement of the draw bar and piston using the support means as a reaction surface causing the tubular member to be withdrawn from the support means. |
