A blade tensioner comprising a blade shoe, a sliding surface with a first
and a second side, a ratchet rod attached to the distal end of the blade
shoe having a length of teeth, and a spring clip for receiving the
ratchet rod and being slidable along the second side of the sliding
surface. When the slack on the chain increases, a distal end of the blade
shoe pivots and slides on the first side of the sliding surface, and the
spring clip slides on the second side of the sliding surface a distance
limited by the engagement of the tab of the spring clip with the
corresponding indentation on the second side of the sliding surface and
the edge of the spring clip engages the teeth of the ratchet rod.