Sollroc Spiral Retrac and Regular Type Tophammer Button bi

Product description In Top Hammer Drilling the hammer produces a percussive force on the drill rods or tubes, which is transmitted to the drill bit. The feed device is usually attached with a hinged boom to a mobile unit. The percussive system strikes the drill rod, for example 2,000-5,000 strikes per minute, and the rotation speed can be, for example, 60-200 rounds per minute. Together these elements make it possible to drill holes in the hard rock. The excess material (cuttings) is flushed up from the bottom of the hole by means of pressurized air or water. Top hammer drills are primarily used in mining, construction and quarrying of rock material. Top hammer drilling, combined with the “drill and blast” method, makes the whole excavation process extremely efficient. SOLLROC stocks a comprehensive supply of Tophammer Drilling Tools. Whether you require bits, coupling sleeves, shank adaptors or rods, we have exactly what you need when you need it. Tophammer drilling principle 1. When the piston hits the shank, kinetic energy in the piston creates a compressive wave in the string of drilling tools, that will cause the bit to penetrate the rock 2. Piston velocity at impact ≈ 10m-s but the compressive wave in the drill steel travels at a velocity of 5180 m-s (velocity of sound in steel) 3. The bit is forced forward and penetrates the rock around 1.0 mm 4. Part of the energy not used to penetrate the rock goes back as a tensile wave and part of it as a compressive wave