Cutter for tunnel boring machine

A cutter for a tunnel boring machine, which cutter comprises a cutter body (1) designed with a slanting surface (2) for interaction with a slanting surface (8) on a cutter ring with a dovetailed foot (3), which may be whole or divided into segments (3a, 3b), which cutter ring (3) has an inner cylindrical contact surface (11), which interacts with an outer cylindrical contact surface (12) on the cutter body (1), whereby

• the cutter body (1) is designed with a threaded portion with threads (6), which interact with corresponding suitable threads on a clamping ring (4), which clamping ring has a slanting surface (5), which interacts with a slanting surface (7) on the cutter ring (3) in order to exert both radial and axial clamping forces on the cutter ring (3) when the cutter ring is secured on the cutter body, further wherein the threads on the cutter body (1) are conically tapered and interact with corresponding conically tapered threads on the clamping ring (4), and that the diameter of the cutter ring's (3) inner cylindrical contact surface (11) has a clearance tolerance relative to the diameter of the outer cylindrical contact surface (12) of the cutter body (1), which clearance tolerance between the cutter ring (3) and the cutter body (1) decreases when the cutter ring is secured to the cutter body by virtue of tightening of the clamping ring (4),
• characterised in that when the ring is clamped on the cutter body, the innermost part of the cutter ring's free lateral surfaces (9, 10) extends outwards at an angle that is at least parallel to the plane through the edge of the cutter ring, but less than perpendicular to said plane.

A cutter for a tunnel boring machine, which cutter comprises a cutter body (1) designed with a slanting surface (2) for interaction with a slanting surface (8) on a cutter ring with a dovetailed foot (3), which cutter ring 3 may be whole or divided into segments (3a, 3b), which cutter ring (3) has an inner cylindrical contact surface (11), which interacts with an outer cylindrical contact surface (12) on the cutter body (1), whereby

• the cutter body (1) is designed with a threaded portion with dreads (6), which interact with corresponding suitable threads on a clamping ring (4), which clamping ring has a slanting surface (5), which interacts with a slanting surface (7) on the cutter ring (3) in order to exert both radial and axial clamping forces on the cutter ring (3) when the cutter ring is secured on the cutter body, further wherein the threads on the cutter body (1) are conically tapered and interact with corresponding conically tapered threads on the clamping ring (4), and that the diameter of the cutter ring's (3) inner cylindrical contact surface (11) has a clearance tolerance relative to the diameter of the outer cylindrical contact surface (12) of the cutter body (1), which clearance tolerance between the cutter ring (3) and the cutter body (1) decreases when the cutter ring is secured to the cutter body by virtue of tightening of the clamping ring (4),
• characterised in that respective ends of the cutter body (1) are attached to a mounting bracket by means of end attachments (21, 22), wherein one of the end attachments is releasable from the mounting bracket such that the cutter ring (3) may be replaced without the cutter being dismantled.