clockwise rotation of spool 47 relative to indexer 62 and thus no feeding of fresh line increments from the windows 49 can take place because of the four short lugs 69 extending radially into interlocking relation you might say 34 splined 34 relation with the medial plane spool stops 60 the initial length of the freely extending cutter line end portions 79 is determined by the manual rotation of the spool 47 before inserting the indexer 62 into the head 15 and at the time the free ends of the double stranded nylon line are respectively being manually withdrawn from spool 47 through line escape windows 49 in the cutter head housing 32 whatever the starting length of cutter line end portions 79 may be the centrifugal forces applied by such line end portions to the double strand turns of nylon line 76 wound on spool 47 which is of course transmitted to the spool to which the inner bight 77 of the line is attached places the spool 47 under a constant clockwise torque this torque is an essential factor in the functioning of the invention as will now be described in detail fig7 shows this torque in action biasing the medial spool stops 60 against the short indexer lugs 69 the clockwise torque constantly imposed on spool 47 by the.