Percussion drilling is employed when auger or wash boring is not possible in very stiff soil or rock. It also can be used in most soil types.
Here the advancement of a hole is achieved by alternatively lifting and dropping a heavy cutting or hammering bit that is attached to a rope or cable that is lowered into an open hole or inside a temporary casing (casings are hollow cylindrical pipes used for borehole stability and to prevent the loss of drilling fluid through the boreholes).
Usually a tripod is used to support the cable. The stroke of bit varies according to the ground condition. The major disadvantage of this method is that it is not possible to get good-quality undisturbed samples. In very hard rock (and especially fractured hard rock), down-the-hole (DTH) drilling can be employed. In this case the hammer, applying repeated percussive pressure, is located just behind the drill bit inside the hole, unlike the open percussion drilling, where the hammer is on top of the drilling string.
The drilling string provides the necessary force and rotation to the hammer and bit, as well as compressed air or fluids to the hammer and for the flushing of cuttings.
This arrangement also allows for much deeper percussion drilling. However, the DTH drills are typically more expensive.
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Environment protection and energy-saving, time-saving and labor-saving
The machine with built-in servomotor direct drive is of low noise, little vibration, low power, high performance, with automatic setting needle count, automatic cutting threads, automatic rewind and other functions. Circle Scissors thread to ensure stable performance, neat incision and nice tangent.
Direct drive motor will save energy
The most energy-efficient lubrication and built-in direct-drive servo motor to achieve the machine's rapid start-up and high braking accuracy; Significantly reduce noise, vibration and energy consumption. The power consumption is less tan 35% of normal drives.
Improve work efficiency
The automatic cut-thread system can automatically cut thread, dial thread, inverted seam, etc. It makes the operation simple and convenient, and can greatly improve work efficiency. Compared with ordinary sewing machine, the productivity will be increased by 15% or more, the machine can be cost-recovery for two years.
Annex installation position
Installed in the machine on the table by mounting accessories, installation accessories such improved operational and durability of machine table.
Roll off the assembly line equipment
Head roll off the assembly line installed at the upper part, the replacement is very convenient off the assembly line, in addition to the cord equipped with a cutter, and after the tangent line volume adjustment device.
Higher lift of the presser foot
The height, 13mm for presser foot lift enables easy material handling.
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High-Speed Single Needle Lockstitch Sewing Machine with Auto-Trimmer
Model NO.: FX9900D
Automatic Grade: Semiautomatic
Type: Sewing Machine
Trademark: FOXSEW
Transport Package: Cartons
Specification: CE
Origin: Zhejiang, China
HS Code: 8452
Direct Drive Computer High-Speed Single Needle Lockstitch Sewing Machine With Auto-Trimmer FX9900D