Tensoning device

Abstract

The present invention relates broadly to a tensioning device (1) for a strata support cable tendon (80). The tensioning device (1) comprises a barrel fitting (60) and a barrel actuator (50). The tensioning device (1) also includes locking means (40) coupled to the barrel actuator (50) for releasable engagement with the barrel fitting (60) to temporarily prevent movement of the actuator (50) relative to the barrel fitting (60). Release of the locking means (40) from the barrel fitting (60) permits longitudinal movement of the barrel actuator (50) relative to the barrel fitting (60) for tensioning of the cable or tendon (80) within the cavity.

Description

FIELD OF THE INVENTION[0001]The present invention relates broadly to a tensioning device for a strata support cable or tendon.BACKGROUND OF THE INVENTION[0002]In underground mining and strata control, bolting is generally recognised as the primary support system. Bolting involves grouting of a rock bolt within a bolt hole formed in the strata of an underground mine. The bolt is tensioned so that the strata surrounding the bolthole is held in compression. This technique has been extended to cables or tendons where a barrel and wedge fitting is attached to the cable and is tensioned using hydraulically actuated equipment. These prior art arrangements suffer from at least the following drawbacks:[0003]i) the tensioning of cables and tendons is time consuming because they comprise multiple stages and thus are expensive operations;[0004]ii) the cables and tendons require relatively large pulling rigs to achieve high tension loads; and[0005]iii) existing designs are large and very heavy t...

AI Technical Summary

Benefits of technology

"The present invention provides a tensioning device for a strata support cable or tendon. The device includes a barrel fitting, a barrel actuator, and locking means. The barrel actuator is movably connected to the barrel fitting for longitudinal movement relative to the barrel fitting. The locking means is operatively coupled to the barrel actuator for releasable engagement with the barrel fitting, or vice versa, to temporarily prevent at least longitudinal movement of the actuator relative to the barrel fitting. The tensioning device allows for the placement of the cable or tendon in a cavity and thereafter release of the locking means to allow for longitudinal movement of the actuator for tensioning of the cable or tendon. The device also includes a strata plate and a bearing assembly to prevent relative rotational movement and allow for angular installation of the cable or tendon. The tensioning device can be used with wire rope or strand as the strata support cable or tendon."

Problems solved by technology

These prior art arrangements suffer from at least the following drawbacks:i) the tensioning of cables and tendons is time consuming because they comprise multiple stages and thus are expensive operations;ii) the cables and tendons require relatively large pulling rigs to achieve high tension loads; andiii) existing designs are large and very heavy to handle creating additional occupational health and safety hazards.

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