Access apparatus with shallow zero closure valve

1. A surgical access assembly for use with a surgical access device, which comprises:

a housing defining a central longitudinal axis;

an elongate access member extending from the housing, the housing and the access member having a longitudinal passage dimensioned to permit passage of a surgical instrument and defining proximal and distal ends; and

a zero closure valve mounted relative to the housing and being adapted to assume an open condition upon passage of the surgical instrument and a substantially closed position in the absence of the instrument, the zero closure valve including a valve periphery having a collar, a tapered segment extending inwardly from the collar and a second segment extending contiguously from the tapered segment, first and second lips depend from the second segment of the zero closure valve and define lip edges which are in approximated closed relation when the zero closure valve is in the closed position to define a slit, the first and second lips each including a proximal lip surface having an outer surface portion and an inner surface portion interconnected by a curved surface, wherein a support rib depends from the proximal lip surface of each of the first and second lips to define a gap therebetween to be in spaced relation when the valve is in the closed position and being positioned to contact the surgical instrument during insertion through the first and second lips.

2. The surgical access assembly according to claim 1 further including an instrument seal disposed within the housing and being adapted to establish a substantial fluid tight seal about the instrument.

3. The surgical access assembly according to claim 1 wherein the second segment extends in a generally perpendicular relation to the central longitudinal axis.

4. The surgical access assembly according to claim 1 wherein the outer surface portion is arranged at a first angle relative to the longitudinal axis.

5. The surgical access assembly according to claim 4 wherein the inner surface portion is arranged at a second angle relative to the longitudinal axis.

6. The surgical access assembly according to claim 5 wherein the second angle is less than the first angle.

7. The surgical access assembly according to claim 5 wherein the first angle is between about sixty-two degrees (62°) to about seventy-three degrees (73°) relative to the central longitudinal axis.

8. The surgical access assembly according to claim 5 wherein the first angle is sixty-seven degrees (67°) relative to the central longitudinal axis.

9. The surgical access assembly according to claim 5 herein the second angle is between about thirty-seven degrees (37°) to about forty-seven degrees (47°) relative to the central longitudinal axis.

10. The surgical access assembly according to claim 5 wherein the second angle is forty-two degrees (42°) relative to the central longitudinal axis.

11. The surgical access assembly according to claim 1 wherein the curved surface includes a radius of curvature ranging from about 0.7 inches to about 0.8 inches.

12. The surgical access assembly according to claim 11 wherein the radius of curvature is 0.75 inches.