Improvements in or relating to male centres for mounting tubular work and to bell centres

摘要

597,197. Lathe centres. BOLD,H. Aug. 13, 1945, No. 20708. [Class 83 (iii)] In a lathe centre, either male or bell-shaped, having hard metal inserts, strips of cemented tungsten or like carbide are brazed into tapered slots and recesses are cut between the strips to accommodate a lubricant such as grease. As applied to a male centre, the strips 5 are inserted into rectangular or undercut slots, which taper from rear to front, brazed to the body 1 and the bearing surface is then ground to the correct form. Between each strip a recess 6 is cut extending either the full length of the strips or shorter and deeper, and formed so as not to impair the security of the strips. The head 9 of a screw 8 and a washer 7 clamped by a collar 4 on a screwed shank 3 protect the ends of the strips and, in the case of the full length recesses, also retain the grease. The bell centre construction is similar.