Kelly drilling

LEFFER offers short-design casing machines (type KL) to support the rotary drilling rig. In general, LEFFER casing machines have been designed based on specific experience. The five-part clamping collar that surrounds the drill pipe prevents plastic damage to the pipe circumference and ensures efficient and force-fit transmission of torques and …

When completing piles in the diameter range 600 to 1500 mm, the use of a a rotary drilling rig is often inefficient. Crane work is required to install the reinforcement, tremie pipes as well as during the subsequent concreting process, for which the drilling rig is only equipped with an auxiliary winch.  To ensure safe retraction of the …

Drilling rigs of the latest generation deliver very high torques, which increasingly means that cased holes can be drilled even to greater depths. For this purpose, longer and longer casings are used, where the rotary adapter must be locked at great heights. It is also sometimes necessary to „untwist“ the casing by pulling it back, which makes …

Retaining clamps are used in the rotary drilling process to prevent the drill string from slipping when the casing is pulled after uncoupling from the adapter. The hydraulic retaining clamp SPA can be supplied via a carrier unit or via a separate hydraulic power pack (E-PP5). The clamping cylinder with load holding valve ensures that the casing …

Augers are used for loosening and conveying dry ground or rock. For drilling in dry ground, LEFFER offers a wide range for dry drilling variants for optimal processing of the subsoil:  The number of cutting edges, the pitch of the auger helix and the type and number of teeth or bits vary depending on the soil conditions. For better …

Der Bohreimer kommt zum Einsatz, wenn in Wasser, Stützflüssigkeit oder sehr weichen, bindigen Böden gebohrt werden muss. Außerdem sorgt er für eine flach geräumte Bohrlochsohle. Der Dreh-Klappboden lässt sich per Rechtsdrehung (Verriegelungsrichtung der Kellystange) öffnen, um Material in den Bohreimer zu fördern. Das Schließen des …

Core barrels are used to cut an annular space in hard rock, boulders or concrete. In order to break the upcoming material with high tension, torque and feed force are concentrated on a relatively narrow ring. Depending on the strength of the rock and the drill diameter, the toothing of the core barrel can be adjusted: For concrete and rock with …

When concreting there is a risk of the concrete segregating in the downpipe. To ensure a safe concreting process, LEFFER has developed a special HD concreting tremie pipe system: The tremie pipe joints we have designed can resist very high tensile forces, which prevents the concreting pipe string from tearing off, even in case of very long pipe …

Decades of practical experience are incorporated in the design and continuous further development of our cutting crowns. For continuous drilling, the tooth system, i.e. tooth shape and number, contact pressure and the corresponding free cut must be correctly selected. The geology of the ground determines the design of the cutting teeth. Taking …

For cased boreholes from a depth of 35 m and a diameter greater than 1500 mm, LEFFER HD has drill pipes in its portfolio that meet the requirements for particularly large drilling depths. Reinforced pipe connectors with backlash-free, conical pipe screws and greater wall thicknesses reduce wear on the drill pipe connectors and also ensure reliable …

For cased boreholes up to a depth of 35 m, LEFFER offers double-walled drill pipes with a usable length of 1 m to 6 m. Our low manufacturing tolerances for diameter, roundness, and straightness pay off on the construction site. Precisely fitting pipe connections ensure quick, straight positioning, screwing, and optimal power transmission. The …