Boring tool with floating blades

In a bearing tool, a combination comprising a tool head having an axis and being provided with a slot extending transverse to said axis;

• a pair of opposite cutting knives floatably mounted in said slot movable away from each other to a cutting position and toward each other to an inactive position, each of said cutting knives having an other cutting edge and an inner end face opposite a corresponding end face of the other cutting knife;
• biasing means cooperating with said cutting knives for biasing the same toward each other to said inactive position;
• spacer means having a pair of opposite faces and a face extending transverse to said opposite faces, said spacer means being movable in said tool head between two positions in one of which said opposite faces respectively engage said inner end faces of said cutting knives to hold the latter in said cutting position in which said cutting edges of said knives are spaced a fixed predetermined distance from each other and in another of which said spacer means permit said cutting knives to move toward each other to said inactive position under the influence of said biasing means;
• stop means arranged for engagement with the transverse face of said spacer means in said one position of the latter;
• and means for moving said spacer means between said one position in which said transverse face of said spacer means engages said stop means to thereby hold said cutting knives in said cutting position, and said other position in which said spacer means permits said cutting knives to move said inactive position.