Linear stapler

1. A surgical stapler, comprising:

a support base;

a trigger located at a proximal end of the support base;

a handle located at a proximal end of the support base;

a retaining pin operatively connected to and extending distally from a support base, the support base being operable in the surgical stapler to cause the stapler to position staples near tissue; and

a unit lockout rotatable about a pivot fixed to the handle, the unit lockout comprising:

an upper end near and under at least one blocking plate in the stapler; and

another end facing the trigger to prevent it from firing when the upper end is blocked from upward movement by the at least one blocking plate,

whereas the upper end of the unit lockout is moved relative to the at least one blocking plate so that the upper end of unit lockout is no longer under the at least one blocking plate to permit the unit lockout to rotate about the pivot.

2. The surgical stapler of claim 1 , wherein the at least one blocking plate comprises a connect cover plate from which the retaining pin is rigidly connected and extended distally, wherein when the retaining pin is not moved distally the connect cover plate blocks the upper end of the unit lockout from moving upward freely.

3. The surgical stapler of claim 1 , wherein the at least one blocking plate comprises at least one lockout plate rigidly connected to a support base movable relative to the handle, the upper end of the unit lockout being movable relative to the lockout plate.

4. The surgical stapler of claim 1 , wherein the at least one blocking plate comprises a connect cover plate from which the retaining pin is rigidly connected and extending distally wherein when the retaining pin is not moved distally the connect cover plate blocks the upper end of the unit lockout from moving upward freely and the at least one blocking plate further comprises at least one lockout plate rigidly connected to a support base which is movable relative to the handle.

5. The surgical stapler of claim 1 , wherein the unit lockout further comprises a lockout knob located adjacent the another end and capable of being slid downwards in a groove formed in an upper portion of the proximal surface of the handle by a user when the retaining pin is moved distally and the upper end is not blocked from upward movement by the at least one blocking plate, so that the unit lockout can be rotated, allowing the trigger to be rotated towards the handle.

6. The surgical stapler of claim 1 , wherein the unit lockout is in an L shape, a blunt triangle shape, a crescent shape, or a gusset shape.

7. The surgical stapler of claim 1 , wherein the unit lockout is made of metal or polymer.

8. The surgical stapler of claim 1 , wherein the retaining pin extends in a direction about parallel to the direction of slide of a connect cover plate rigidly connected to the retaining pin slidable on the support base but is off set upward from the slidable connect cover plate by 1 cm to 10 cm.

9. The surgical stapler of claim 1 , wherein the pivot is located at an upper portion of the handle.

10. The surgical stapler of claim 1 , wherein the retaining pin is connected to a push button via a connect cover plate operatively.

11. The surgical stapler of claim 1 , wherein when the retaining pin is shifted distally but not properly positioned yet, the unit lockout is rotated an angle smaller than a threshold angle and the trigger cannot be fired, when the unit lockout is rotated continuously as desired by the operator and beyond the threshold angle, the upper end will push the retaining pin to position it properly, so that the trigger can be fired.