Abstract: A knife holder for cutting machines, with a cutter head (1) for holding a knife (2) and a positioning device (3), wherein the positioning device (3) can be driven in a drive direction (4) between a standby position and a cutting position, and comprises a spring (5), with which the positioning device (3) is applied against the drive direction (4), wherein the spring (5) generates a reset force having a negative force characteristic curve in the drive direction (4).

Abstract: The present invention relates to a knife holder for cutting machines, with a cutter head (1) for holding a knife (2) and a positioning device (3), wherein the positioning device (3) can be driven in a drive direction (4) between a standby position and a cutting position, and comprises a spring (5), with which the positioning device (3) is applied against the drive direction (4), wherein the spring (5) generates a negative force characteristic curve in the drive direction (4).

Abstract: A screw-type compressor having a motor driven and dry operating compressor unit. A butterfly valve is disposed in an intake line connected to the suction side of the compressor unit. An adjustment cylinder mechanically shifts the butterfly valve. A pressure line is connected to the pressure side of the compressor unit and, via the interposition of a check valve, is connected to a compressed air system. The pressure line is connected to a pneumatically controlled air relief valve via an air relief line for relief of pressure during idling of the compressor unit. At least during idling, the air relief valve is adapted to be acted upon by the pressure that is effective on the pressure side of the compressor unit.