Rod locking apparatus

Abstract

A rod locking apparatus includes a housing which includes a first tubular passage and a second tubular passage which are arranged to intersect with each other, the first tubular passage including a serrated locking surface, and a wedge piston slidably arranged in the first tubular passage. The wedge piston includes a front side which includes a wedge surface which engages an end surface of a rod to be locked, and a serrated rear side which engages with the serrated locking surface.

What is claimed is: 
     
         1 - 27 . (canceled) 
     
     
         28 . A rod locking apparatus comprising:
 a housing comprising a first tubular passage and a second tubular passage which are arranged to intersect with each other, the first tubular passage comprising a serrated locking surface; and   a wedge piston slidably arranged in the first tubular passage, the wedge piston comprising a front side which comprises a wedge surface which is configured to engage an end surface of a rod to be locked, and a serrated rear side which is configured to engage with the serrated locking surface.   
     
     
         29 . The rod locking apparatus as recited in  claim 28 , wherein,
 the serrated locking surface is arranged to be integral with the housing, or   the serrated locking surface is arranged on a separate support part which is fixed relative to the housing.   
     
     
         30 . The rod locking apparatus as recited in  claim 28 , wherein the serrated rear side of the wedge piston is inclined at an angle of between 10 and 20° relative to the wedge surface. 
     
     
         31 . The rod locking apparatus as recited in  claim 28 , wherein the first tubular passage extends at an angle of between 100 and 110° relative to the second tubular passage. 
     
     
         32 . The rod locking apparatus as recited in  claim 28 , wherein the wedge piston is movable between a closed position in which the wedge piston substantially blocks the second tubular passage, and an open position in which the second tubular passage is open. 
     
     
         33 . The rod locking apparatus as recited in  claim 32 , wherein the wedge piston further comprises a through passage which is arranged to extend from the front side to the serrated rear side of the wedge piston generally parallel to the second tubular passage so that, when the wedge piston is in the open position, the through passage is generally coaxial with the second tubular passage, and when the wedge piston is in the closed position, the through passage is not aligned with the second tubular passage. 
     
     
         34 . The rod locking apparatus as recited in  claim 32 , wherein the wedge piston further comprises two end surfaces which extend generally perpendicular to the serrated rear side of the wedge piston. 
     
     
         35 . The rod locking apparatus as recited in  claim 34 , wherein,
 the two end surfaces comprise a first end surface,   the first tubular passage further comprises a first end and a second end, and   the first end surface comprises a first piston face on which a pressurized fluid introduced into the first end of the first tubular passage acts to push the wedge piston along the first tubular passage towards the second end of the first tubular passage.   
     
     
         36 . The rod locking apparatus as recited in  claim 35 , wherein,
 the two end surfaces further comprise a second end surface, and   the second end surface comprises a second piston face on which a pressurized fluid introduced into the second end of the first tubular passage acts to push the wedge piston along the first tubular passage towards the first end of the first tubular passage.   
     
     
         37 . The rod locking apparatus as recited in  claim 36 , wherein,
 a movement of the wedge piston from the open position to the closed position comprises a movement of the wedge piston from the second end of the first tubular passage towards the first end of the first tubular passage, and   a movement of the wedge piston from the first end of the first tubular passage towards the second end of the first tubular passage.   
     
     
         38 . The rod locking apparatus as recited in  claim 36 , wherein,
 the first piston face comprises a first piston face surface area,   the second piston face comprises a second piston face surface area, and   the first piston face surface area is greater than the second piston face surface area.   
     
     
         39 . The rod locking apparatus as recited in  claim 35 , wherein the housing further comprise a first end cap which is configured to close the first tubular passage at the first end. 
     
     
         40 . The rod locking apparatus as recited in  claim 39 , wherein the first end cap comprises an aperture and a pressurized fluid supply device configured to supply a pressurized fluid into the first end of the first tubular passage via the aperture in the first end cap. 
     
     
         41 . The rod locking apparatus as recited in  claim 40 , wherein the housing further comprises a second end cap which is configured to close the first tubular passage at the second end. 
     
     
         42 . The rod locking apparatus as recited in  claim 41 , wherein the second end cap comprises an aperture and a pressurized fluid supply device configured to supply a pressurized fluid into the second end of the first tubular passage via the aperture in the second end cap. 
     
     
         43 . The rod locking apparatus as recited in  claim 42 , wherein,
 the wedge piston further comprises a bore, and   the housing further comprises a supply tube which extends from the aperture in the second end cap into the bore in the wedge piston,   the rod locking apparatus further comprising:   a seal arranged between the supply tube and the wedge piston, the seal being configured to provide a substantially fluid tight seal between an interior surface of the wedge piston surrounding the bore and an exterior surface of the supply tube.   
     
     
         44 . An assembly comprising:
 the rod locking apparatus as recited in  claim 28 ; and   a rod arranged in the second tubular passage, the rod comprising a rod first end which is arranged in the second tubular passage and a rod second end which is arranged to extend out of the second tubular passage.   
     
     
         45 . The assembly as recited in  claim 44 , wherein,
 the rod first end comprises a rod first end surface area,   the serrated locking surface comprises a serrated locking surface area, and   the serrated locking surface area is greater than the rod first end surface area.   
     
     
         46 . A rod locking apparatus comprising:
 a housing comprising a first tubular passage and a second tubular passage which are arranged to intersect with each other, the first tubular passage comprising a first end and a second end; and   a wedge piston slidably arranged in the first tubular passage, the wedge piston comprising a front side which comprises a wedge surface which is configured to engage an end surface of a rod to be locked, a rear side, and a first end surface and a second end surface which each extend generally perpendicular to the rear side of the wedge piston, the wedge piston being movable between a closed position in which the wedge piston substantially blocks the second tubular passage, and an open position in which the second tubular passage is open,   wherein,   the first end surface comprises a first piston face on which a pressurized fluid introduced into the first end of the first tubular passage acts to push the wedge piston along the first tubular passage to the second end of the first tubular passage,   the second end surface comprises a second piston face on which a pressurized fluid introduced into the second end of the first tubular passage acts to push the wedge piston along the first tubular passage to the second end of the first tubular passage,   a movement of the wedge piston from the open position to the closed position comprises a movement of the wedge piston from the second end of the first tubular passage to the first end of the first tubular passage, and vice versa, and   a surface area of the first piston face is greater than a surface area of the second piston face.