公开(公告)号：WO1990006826A1

公开(公告)日：1990-06-28

申请号：PCT/US1989005473

申请日：1989-12-04

Applicant: HUCK MANUFACTURING COMPANY

Inventor： HUCK MANUFACTURING COMPANY ,  PORT, Gary, L. ,  KAELIN, John, J.

IPC: B21J15/02

CPC classification number: B21J15/22 ,  B21J15/022 ,  B21J15/105 ,  B21J15/326 ,  Y10T29/53748

Abstract: A push-pull tool for setting multi-piece fasteners (16) includes a piston (10) that is movable back and forth within a cylinder (12) in response to fluid forces on opposite faces of the piston (10). One of the fluids is an air-oil foam mixture that acts essentially as an incompressible liquide force-transmitter, while being somewhat compressible so as to absorb shock loadings associated with rapid piston movements. A check valve (55) is included in the system to admit atmospheric air into the air-oil foam mixture, to thereby partially compensate for oil leakage that might inadvertantly take place across the piston seals.