Abstract: An adjustable seat post arrangement, including a seat post, a pneumatic cylinder, a pressure vessel, a control valve and a valve actuating means, wherein the seat post is operatively connected to a cylinder barrel of the pneumatic cylinder, wherein the pneumatic cylinder includes a first chamber, which is situated on one side of a piston, and includes an open second chamber, which is situated on an opposite side of the piston, wherein the control valve is actuatable by the valve actuating means, wherein compressed air can be fed from the pressure vessel via lines and the control valve to the first chamber, wherein a first line leads from the control valve to the first chamber, and wherein a pressure spring which acts on the piston is provided in the open second chamber.

Abstract: An adjustable seat post arrangement, including a seat post, a pneumatic cylinder, a pressure vessel, a control valve and a valve actuating means, wherein the seat post is operatively connected to a cylinder barrel of the pneumatic cylinder, wherein the pneumatic cylinder includes a first chamber, which is situated on one side of a piston, and includes an open second chamber, which is situated on an opposite side of the piston, wherein the control valve is actuatable by the valve actuating means, wherein compressed air can be fed from the pressure vessel via lines and the control valve to the first chamber, wherein a first line leads from the control valve to the first chamber, and wherein a pressure spring which acts on the piston is provided in the open second chamber.

Abstract: Hard metal cutting blades are inserted into grooves of the rotor body. Each cutting blade is provided at both ends thereof with a cylindrical or conical clamping surface, to which a conical surface of a conical screw is applied which clamps the blade within the groove by a clamping force. The cutting blades are thus securely held in a definite position not only radially and circumferentially, but also axially. The shape of the cutting blades and the grooves as well as the clamping means, having the shape of conical screws, are simple and unexpensive, and their handling is simple. A soiling of the cutting blade clampings is virtually excluded.