Sandvik Ab

Sandvik Aktiebolag

Eric Tjernstrom

Anna Hedberg

Boring bar

A toolholder forms a seat in which a cutting insert is seated. The insert is held in place by a clamp having front and rear portions. The front portion engages within a center hole of the insert, and the rear portion engages an inclined surface of the toolholder so that the clamp is pushed downwardly and rearwardly when attached by a screw. A coil spring surrounds the screw and is compressed between the clamp and the toolholder to bias the clamp upwardly. An upper end of the spring is disposed in a bore of the clamp which is inclined relative to the screw, whereby the spring abuts a rear portion of a wall of the bore to bias the clamp rearwardly as well as upwardly.

Toolholder for indexable inserts

A cutting insert has top and bottom surfaces and a center hole extending between those surfaces. The insert is seated in a pocket of a toolholder. A clamp is attached to a body of the toolholder by a screw which extends through a through-hole of the clamp and is threadably engaged with the body. An inner end of the clamp engages the body, and a projection at the outer end of the clamp enters the center hole of the insert. When the clamp is tightened, it is displaced downwardly such that a planar under surface of the clamp pushes downwardly against the insert, and is also displaced inwardly so that the projection of the clamp pushes the insert rearwardly against an upright support surface. The inward displacement of the clamp is achieved by causing the inner end of the clamp to engage an inclined surface of the body, or by causing a head of the screw to displace the clamp inwardly.

A tool clamping device for machine tools comprises a draw bar that is axially displaceable inside a machine spindle and a locking element arranged in cooperation with the draw bar. The device becomes secured to a toolholder by effecting a relative movement between the draw bar and the locking element to effect a lateral displacement of the locking element into locking engagement with a shaft portion of the toolholder. Continued axial movement of the draw bar is transmitted as axial movement to the toolholder.

Growing community of inventors

Gavle, Sweden

Eric Tjernstrom