Rotary knife cutting systems

1. A rotary cutting system for use with a surgical stapling device comprising:

a knife blade having a distal cutting edge and a proximal base;

a support base positioned within a surgical stapling device;

a mainspring for imparting motion to the knife blade relative to the support base; and

a hammer member interposed between the knife blade and the mainspring, the hammer member being engageable with the proximal base of the knife blade, wherein a first end of the mainspring is attached to the support base and a second end of the mainspring is engageable with the hammer member.

2. The rotary cutting system as recited in claim 1 , wherein the hammer member has a first surface engageable with the proximal base of the knife blade.

3. The rotary cutting system as recited in claim 2 , wherein the first surface of the hammer member frictionally engages the proximal base of the knife blade.

4. The rotary cutting system as recited in claim 2 , wherein the mainspring is releasable from a wound condition storing energy to an expanded condition releasing energy such that the mainspring imparts a rotary motion to the hammer member as the mainspring moves from the wound condition to the expanded condition.

5. The rotary cutting system as recited in claim 4 , wherein the knife blade is a circular cutting blade.

6. The rotary cutting system as recited in claim 5 , wherein the hammer member has a slot and the second end of the mainspring has a tab engageable with the slot such that the tab moves radially outward in the slot as the mainspring moves from the wound condition to the expanded condition.

7. The rotary cutting system as recited in claim 1 , further comprising a latch mechanism engageable with the hammer member to releasably restrain the hammer member against the bias of the mainspring.