Lock spring and cutting tool having a lock spring

A cutter head portion of a rotatable gear cutting tool, said cutter head being disc-shaped and having a periphery, said cutter head comprising a plurality of cutting blade mounting slots and at least one adjustment screw, said at least one adjustment screw being operable to advance inward into at least one of said cutting blade mounting slots and to withdraw in a direction opposite to the advance inward movement,

• said at least one adjustment screw comprising a head portion and a shaft portion wherein at least a part of said shaft portion comprises threads,
• said at least one adjustment screw being located in an opening in said cutter head, said opening extending from said periphery to said at least one cutting blade mounting slot, an inner portion of said opening being threaded and in threaded engagement with the threads of said shaft portion,
• a spring located between said inner portion of said opening and a back surface of said head portion of said at least one adjustment screw, said spring being in contact with said back surface,
• said cutter head portion further comprising at least one clamp screw and at least one clamp block, said at least one clamp block being positioned in at least one of said cutting blade mounting slots and being operable to clamp a cutting blade in position in at least one of said cutting blade mounting slots,
• wherein at least one clamp screw and at least one adjustment screw contact said at least one clamp block in said at least one of said cutting blade mounting slots.