Hydraulic screw tensioner

Abstract

A hydraulic screw tensioning device includes a tubular body, with a through opening and an annular cylinder chamber surrounding the through opening, and a tubular piston movably supported in the tubular body and connectable to a screw to be tensioned. The tubular piston includes a stepped outer portion and divides the annular cylinder chamber into a first pressure chamber and a second pressure chamber. The second pressure chamber is closed by an annular end cap secured to the tubular body. The first pressure chamber is connectable to a pressure source for hydraulic fluid. The second pressure chamber is connectable to a pressure source for a compressible medium via a conduit connector mounted on the annular end cap. The conduit connector extends radially in relation to a geometric axis (A-A) of the tubular body. A damage protecting structure is provided to protect the conduit connector against accidental physical damage.

1 - 4 . (canceled) 
     
     
         5 . A hydraulic screw tensioning device comprising a tubular body, with a through opening and an annular cylinder chamber surrounding the through opening, and a tubular piston movably supported in the tubular body and connectable to a screw to be tensioned, the tubular piston comprising a stepped outer portion and dividing the annular cylinder chamber into a first pressure chamber and a second pressure chamber, wherein:
 the second pressure chamber is closed by an annular end cap secured to the tubular body,   the first pressure chamber is connectable to a pressure source for hydraulic fluid,   the second pressure chamber is connectable to a pressure source for a compressible medium via a conduit connector mounted on the annular end cap,   the conduit connector extends radially in relation to a geometric axis (A-A) of the tubular body, and   a damage protecting structure is provided to protect the conduit connector against accidental physical damage.   
     
     
         6 . The hydraulic screw tensioning device according to  claim 5 , wherein:
 the conduit connector is mounted on the annular end cap and communicates with the second pressure chamber; and   the damage protecting structure forms an integrated part of the annular end cap.   
     
     
         7 . The hydraulic screw tensioning device according to  claim 6 , wherein the damage protecting structure comprises two protrusions extending radially from the annular end cap. 
     
     
         8 . The hydraulic screw tensioning device according to  claim 5 , wherein the annular end cap is secured to the tubular body in at least two alternative angular positions enabling the conduit connector to occupy different radial directions in relation to the tubular body. 
     
     
         9 . The hydraulic screw tensioning device according to  claim 6 , wherein the annular end cap is secured to the tubular body in at least two alternative angular positions enabling the conduit connector to occupy different radial directions in relation to the tubular body. 
     
     
         10 . The hydraulic screw tensioning device according to  claim 7 , wherein the annular end cap is secured to the tubular body in at least two alternative angular positions enabling the conduit connector to occupy different radial directions in relation to the tubular body.