{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

9781439834220.ch10

10212 disc type in this type of ripper unit there are

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: full face has been cut, the machine is moved forward. 10.2.1.2 Disc type In this type of ripper unit, there are two cutting heads, each consisting of two vertical discs laced with tipped bits. The cutting heads are carried in the front end of an extension boom. In this machine the cutting heads are rotated and at the same time a to-and-fro movement of about 25 times/minute is imparted to the gear case and the cutting heads. The resulting motion, therefore, of each pick is spiral which results in low consumption of power and less degradation of rock/coal. In one of the designs, for example, the cutting head cuts a kerf of 2.5 m wide and 0.6 m deep. The discs rotate at the speed of 75 r.p.m. The cutting head can be lowered or raised hydraulically. Apart from the cutting head, the machine has got an apron with gathering arms, a conveyor extending up to the rear of the machine and crawler tracks. These types of machines can be operated for the coal seams having thickness range 1–3 m. Different combinations of ripper type boom headers with different muck loading units include backhoe excavator loading the muck into trucks; cutter boom dischar ging muck on to a chain conveyor unit for its onward transportation into trucks and the integral unit gathering arms of a ripper-heading machin...
View Full Document

{[ snackBarMessage ]}