Patent ID: 8544253

Claim:
A device ( 10 ) for on-site fitting and extraction of pivot pins ( 12 ) of chain links ( 14 , 16 ) which comprise an alternating sequence of external links ( 14 ) and internal links ( 16 ), each external link ( 14 ) comprising parallel side pieces ( 34 , 26 ) with pierced ends ( 30 , 32 ) having corresponding end piercings ( 31 , 33 ), each internal link ( 16 ) comprising two parallel side pieces ( 20 , 22 ) with pierced ends ( 24 , 26 ) having corresponding end piercings ( 25 , 27 ), a tubular spacer ( 28 ) joining together the parallel side pieces of the external links and the parallel side pieces of the internal links at the pierced ends of the parallel side pieces of the external links and at the pierced ends of the parallel side pieces) the internal links, the external links and the internal links being articulated at said pierced ends of the parallel side pieces of the external links and the parallel side pieces the internal links via associated pivot pins ( 12 ), said device ( 10 ) comprising: i) a pair of portable cylinder supports ( 46 ), fittable on-site by an operator at the pierced ends of a first of said external links ( 14 ); ii) two hydraulic cylinders ( 44 ) synchronized in displacement, each of the said hydraulic cylinders ( 44 ) received in a respective one of the supports ( 46 ), each of the said hydraulic cylinders ( 44 ) arranged to selectively stress i) an associated one of the pivot pins ( 12 ) of said first external link or ii) one of the parallel side pieces ( 32 ) of said first external link ( 14 ), the stress being sufficient to push the associated one pivot pin ( 12 ) through one of the end piercings ( 31 , 33 ) of said first external link ( 14 ), together with aligned end piercings ( 25 , 27 ) of an associated one of the internal links ( 16 ), and an associated one of the spacers ( 28 ), to simultaneously insert or extract the pins ( 12 ) associated with the pierced ends of said first external link ( 14 ); iii) a control device ( 48 ) common to the two cylinders ( 44 ); and iv) a pair of lateral ducts ( 450 , each lateral duct ( 45 ) connecting the control device to a corresponding one of the hydraulic cylinders, wherein each hydraulic cylinder ( 44 ) comprises a tubular body ( 52 ) with a movable hydraulic piston connected to a corresponding one the lateral ducts ( 45 ), a rod ( 50 ) moved by movement of the hydraulic piston, and wherein each said tubular body ( 52 ) is mounted to pivot axially relative to the associated cylinder support to allow a selective orientation of the corresponding one lateral duct according to space available around the associated cylinder support.