Safety device for key-actuated, rotating chucking means

摘要

Chuck keys for rotating chucking means are sometimes used without any safety feature to prevent being thrown out when the machine starts. There is consequently a considerable risk of injury for persons located in the flight area of the chuck key. Chuck keys with a push-out pin or sleeve require an additional push-in force and thus sometimes two-handed operation during the rotary movement. Protective hoods over the chucking means must be opened and closed by additional manipulations. The machine can only start when the chuck key (1, Fig. 1) is put away in the chuck-key holder (2). The inductive proximity switches (3) are here influenced by recesses and damping surfaces (coding) of the chuck key in such a way that the electric circuit (2, sheet 2) of the machine is closed. The holding circuit (4, sheet 2) necessary for normal use of the machine is forcibly (S3) interrupted during switch-on and at the same time serves as a reclose safety feature. The chuck key of the jaw chuck of the lathe represents a typical example of possible cases. <IMAGE>