Piston, in particular for sampling valve
OwnerPascal Favreinventor
Life of this patent
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Abstract
The invention concerns a piston wherein the mobile screw (2) is engaged in the bolt (8) integral with the mobile assembly (1). It is provided with a cylindrical axial housing (10) wherein is engaged the rod (7) integral at its front end with the expander assembly (4). At the end of its front travel, the rod is retained by its flange (19) pressed on the stop (11) such that the expanding ring (5) is compressed by the thrust of the piston body (3) and causes the flexible envelope (6) to expand.
Claims11
A piston, in particular for a draw-off valve, comprising a piston body (3) covered externally with an extensible casing (6), a displacement screw (2) provided with rotational driving means (20) and cooperating with a nut (8) immovably attached to the piston body (3) for displacement thereof in response to the rotations of the screw, and a dilating device linked to the piston and causing, at the limit of travel, a dilation of the casing (6), characterised in that the dilating device comprises a dilating disk (4) and a rod (7) having one end immovably attached to the disk, and in that the screw (2) has on the one hand a longitudinal housing (10) in which the rod (7) is fitted and on the other hand at its front end a limit stop (11) which cooperates at the limit of travel with a collar (19) of the rod situated at its back end, so as to cause a squeezing of the dilating disk (4) against the end of the piston body and a radial expansion of said dilating device.
Dependencies are inferred from the claim text.