欧美日本激情三级在线观看,玖玖搡逼视频玖玖,无码精品一区二区三区四区爱奇艺,亚洲人成网站999久久久全网,年轻国产一级黄片

Tackle is divided into single-wheel tackle, double-wheel tackle and multiple –wheel tackle according to wheel number; it is also classified into hook tackle, chain ring tackle, ring tackle and hanging beam tackle according to the connection way between tackle and hanging objects. General speaking, most of small or medium sized tackles fall into hook tackle, chain ring tackle and ring tackle while large sized tackles are usually ring tackle or hanging beam tackle; it is categorized into tackle with sliding bearing mounted between axles and tackle with rolling bearing mounted between axles according to the joint of wheel and axle; it can be divided into opened tackle and closed tackle according to splint. The splint of opened tackle can be opened to facilitate installing cable and most of opened tackles are single wheel tackle which is used as guide tackle at the bottom of standing derrick; it can be divided into fixed tackle and movable tackle according usage way. It is convenient to use tackles which can be widely used in places such as factory, mine, agriculture, electricity power, construction, wharf, dock, machine installation in warehouse and cargo lifting in a manual and mechanical way.