DEVICE FOR CUTTING OF HOLE IN ACTIVE PIPELINE Russian patent published in 2000 - IPC

FIELD: mechanical engineering. SUBSTANCE: device may be used for working on active pipeline being under operating medium pressure. The device body accommodates spindle with cutting tool at its lower end, mechanism of forward movement and mechanism of rotary movement. Mechanism of spindle forward movement represents screw, nut and upper and lower cylinders positioned along spindle axis. One end of screw is secured in holder above spindle, and other end is arranged inside spindle. Nut is screwed on screw, and it thrusts into upper end of spindle. Internal diameter of upper cylinder exceeds external diameter of spindle. Upper cylinder is coupled with nut and provided with thread. Lower cylinder, internal diameter of which is also larger than external diameter of spindle, is coupled with body and provided with thread corresponding to thread of lower cylinder. Length of screw is equal to length of all connecting members located between device and pipeline. Length of each cylinders is equal to or larger than depth of hole being cut out along with a space necessary for engagement of thread of upper and lower cylinders. Pitch of screw and nut thread may exceed thread pitch of upper and lower cylinders. In mechanism of spindle rotary movement motor and movement transmission mechanism may be connected by coupling. EFFECT: improved conditions of cutting. 3 cl