A tool comprising a burr cutter 34 and a guide 2, the guide 2 comprising: a body portion 4 having first and second guide surfaces 12a, 12b which are spaced from one another to define a slot 14 between the first and second guide surfaces 12a, 12b; a bearing 32a, 32b for rotatably mounting the body portion 4 to a shank 38 of the burr cutter 34 with a cutting head 36 of the burr cutter 34 adjacent the slot 14; wherein the first and second guide surfaces 12a, 12b and the bearing 32a, 32b are positioned relative to one another such that the first and second guide surfaces 12a, 12b are tangential to the cutting head 36 of the burr cutter 34.

Die Erfindung betrifft eine Vorrichtung (1) zum Bearbeiten von bevorzugt plattenförmigen Werkstücken (30), die bevorzugt zumindest abschnittsweise aus Holz, Holzwerkstoffen, Kunststoff oder dergleichen bestehen, mit einer auf das Werkstück (30) einwirkenden Werkzeuganordnung (10), die zumindest ein Werkzeug (12) aufweist, und einer Tasteinrichtung (14) mit wenigstens einer Tastrolle (16), die um ihre Rotationsachse (17) drehbar gelagert ist und die die Lage des Werkzeugs (12) relativ zum Werkstück (30) steuert. Die erfindungsgemäße Vorrichtung ist dadurch gekennzeichnet, dass die Tastrolle (16) mittels einer Stellanordnung (20) derart gelagert ist, dass ihre Rotationsachse (17) relativ zu dem zugeordneten Werkzeug (12) verstellbar ist.

An orbital machining apparatus for producing a hole and/or a recess in a workpiece by means of a cutting tool, said apparatus comprising:

a first, second and a third actuator (52,60, 58); a radial offset mechanism configured for controlling the radial distance of the center axis of the cutting tool from a principal axis, said radial offset mechanism comprises:

an inner cylindrical body and an outer cylindrical body (64); and

a mechanism for locking the outer and inner cylindrical bodies (64, 62) together after setting a desired eccentricity thereof. The locking mechanism comprises mutually matching tapered surface sections (72, 74) adjacent front end portions of the outer and inner cylindrical bodies (64, 62), and a tightening nut (70) acting on a rear end portion of either one of the cylindrical bodies for clamping the tapered surfaces (72, 74) together to thereby fixate the mutual rotary positions of the cylindrical bodies (62, 64). The invention also relates to a radial offset mechanism of such an apparatus.

An engine includes a cylinder block (1) including a cylinder hole (2), a crank shaft (6) as an offset crank, and a connecting rod (5) for connecting the piston (4) and the crank shaft (6). An inclined surface (11) is formed on the entire circumference of a crank-shaft-side opening edge of one end of the cylinder hole (2). When viewed in the axial direction of the crank shaft (6), a boundary line (34) between the inclined surface (11) and the cylinder hole (2) approaches the other end of the cylinder hole (2) as going toward an offset side on which the crank shaft (6) is offset from the central line of the cylinder hole (2). This invention can provide an offset crank type engine in which the entire circumference of the crank-shaft-side opening edge of the cylinder hole can be chamfered without adopting any arrangement having a bad influence on the sliding surface and posture of the piston, in order to avoid interference between the crank-shaft-side opening edge of the cylinder hole and the connecting rod.