CIRCULAR STAPLING DEVICE WITH OFFSET SPLINE TIP

A surgical stapling device includes an anvil assembly and a shell assembly. The anvil and shell assemblies each include splines that define guide channels. Each of the anvil splines defines a distally positioned triangular tip that is defined by an apex and first and second right cam surfaces. The cam surfaces of the anvil splines are configured to engage one of the shell splines to cam or rotate the anvil assembly into alignment with the shell assembly as the anvil assembly is moved in relation to the shell assembly to a clamped position. The apex of each of the anvil splines is offset from a longitudinal axis of the anvil spline such that the first and second cam surfaces of the anvil splines define a short edge and a long edge and have surfaces that have different surface areas. By providing anvil splines that have cam surfaces with different surface areas, a greater force is applied to the cam surface having a greater surface area when the apexes of the anvil and shell splines "crash". As such, when spline crashing occurs, the anvil splines are pushed in one direction to rotate the anvil assembly in relation to the shell assembly to direct the anvil splines into the guide channels defined by the shell splines to properly align the shell assembly with the anvil assembly.