20140182838 | MULTI-LEVEL SLIDING SLEEVE - A multi-level sliding sleeve including an outer cylinder, an inner sliding sleeve, a combined ball socket, a guider, an expander, an upper gland, a lower gland, and a ball. The outer cylinder includes internal threads in an upper end and external threads in a lower end, and the outer cylinder including an external wall including a plurality of drainage holes along the peripheral direction. The inner sliding sleeve is mounted to an inner wall of the outer cylinder through shear pins. The inner sliding sleeve includes a plurality of square holes in the middle along the peripheral direction, each of which is equipped with a ball socket inside. The ball sockets combine together to form a combined ball socket. The combined ball socket is equipped with the guider in the upper end and the expander in the lower end. | 07-03-2014 |