Patent ID: 9291037
Filing Date: 2016-03-22
CPC Classification: E21B

Claim Text:
1. A cutting unit for a hydro-mechanical slot-type perforator having a longitudinal axis, said cutting unit is mounted in a casing; said cutting unit is associated with and driven by a pusher capable of moving in the casing; said cutting unit comprises: a number of cutting tools; a first holder immovable relative to the pusher; a second holder immovable relative to the casing; the first holder and the second holder are capable of rotation; a balance beam rotatable around an axle; said balance beam is assembled in the casing between the first holder and the second holder; said balance beam is capable of pairwise interaction with the first holder and the second holder causing a rotation of said balance beam, with an extension and a retraction of said cutting tools from and into the casing respectively; said balance beam includes shoulders, containing at least some of said cutting tools; wherein said axle is adapted to move along the longitudinal axis, and wherein said casing having an edge with a specific edge shape; said cutting unit further comprising: a retractable mechanism for bringing said cutting unit into a transportation position and fixing said cutting unit therein; said retractable mechanism includes: a recess made in the first holder; said recess has a shape similar to, or capable of cooperating with said specific edge shape, thereby providing for fixation of the first holder in the casing, absence of pressure applied to the pusher.