A safety trocar is provided which includes a spring-loaded shield that shields the cutting tip of the obturator after the obturator penetrates tissue. The distal end of the shield is hemispheric in profile and contains a slot which conforms to the geometry of the cutting tip. The rounded distal end enables...http://www.google.com/patents/US5399167?utm_source=gb-gplus-sharePatent US5399167 - Safety trocar
