Plug-in socket with blocking member

A plug-in socket for amplifiers, loudspeakers boxes, and electrical musical instruments, comprising

• a socket member with a round inner bore and having an opening therein for receiving an electrical plug,
• a housing member located behind said socket member, and being attached to said socket member by a step, said housing member having at least two contact clamps therein,
• a blocking member partially insertable into said opening of said socket member, said blocking member including a lock housing, a tubular member extending from said lock housing and passing through said round inner bore of said socket member, said tubular member being closely supported within said round inner bore of said socket member thereby securing a fixed central position of said blocking member within said inner bore of said socket member, a rotatable elongated actuating member extending centrally through said tubular member and having a projecting member at a forward end thereof, said projecting member being disposed eccentrically with respect to a longitudinal axis of said elongated actuating member, and a movable pin supported on said tubular member which is engaged by said projecting member, so that when said pin is in a first position, said pin is completely within said tubular member, and when said actuating member is rotated, said pin is moved by said projecting member into a second position wherein said pin is at least partially outside of said tubular member and will engage against said step, thereby preventing removal of said blocking member from said socket member.