GB1527601A - Jack for stressing and anchoring tendons - Google Patents

Abstract

1527601 Post-tensioning jacks BUILDINTER AG 8 Dec 1975 [10 Dec 1974] 53372/74 Heading F2G An hydraulic jack 1 for simultaneously pre- or part-tensioning a plurality of tendons and subsequently anchoring same comprises a cylinder 1 having a mouth 13 at its front end to receive the tendons; a gripping member 35 for the tendons which is adapted to be removed through the mouth and is adapted to be rearwardly actuated by the piston means 17, 19 to stress the tendons and an annular lock-off piston and cylinder assembly 6a, 67 which is adapted to drive via actuating means a lock-off plate 91 forwardly to anchor the tendons; the lock-off piston 69 being located forwardly of the piston means 17, 19 and the actuating means including a ring member 101 which is located forwardly of the member 35 and is removable through the mouth without removal of the lockoff piston 69 to permit removal of the gripping member 35. The member 35 is apertured to receive split wedges 41 composed of segments 42 which are each surmounted by a spring- loaded sleeve 45; the springs 47 acting on the sleeves bearing against a fixed plate 51. A plate 53 is mounted in front of the gripping plate 35 for limited axial movement relative thereto and is provided with apertures 57 for the passage of the tendons. The unit 35, 51, 53 is removed by unscrewing the ring 101 and a further ring 107; the ring 101<SP>1</SP> in a modification being secured to its associated ring 95<SP>1</SP> by a spring-loaded detent, see Fig. 2 (not shown).