The hydraulic casing oscillators have been designed in accordance wiht the latest technical know-how. Extremely sturdy construction gaurantees worth-while use on site. By means of exact statical calculations in conjunction with higher quality material, an optimum conformity of loads, weight and material strength is achieved. The internal welding stresses, not easily determined for the statical calculation, and which would affect the construction considerably, are eliminated by means of stress relieving prior to machining.
A prominent feature of the equipment is the clamping collar consisting of five links operating on the boring implement. The individual links surround the casing like a chain so that a constant surface pressure is exerted on the casing circumference. In addition, the large height of the collar (400 to 700 mm) prevents any damage to the casings. By means of easily exchangeable reducer pieces the oscillator can be converted, within a few minutes, to a smaller casing diameter. The collar opens uniformly and enables unproblematic insertion of the casing with the cutting shoe. Another advantage of the machine is the low height on the excavator side.
The hydraulic retaining clamp type SPA guarantees a safe grip of the casing column, while retracting the casings with the drilling rig.