|국가/구분||United States(US) Patent 등록|
|발명자 / 주소|
|출원인 / 주소|
|인용정보||피인용 횟수 : 0 인용 특허 : 81|
A check valve having a piston-like ball or stopper a pre-determined distance from the valve seat so that the ball or stopper seats against the valve seat only under backflow pressure.
I claim: 1. A surgical handpiece used to perform liquefaction during a cataract procedure, comprising: a hollow housing having a stem valve seat; a stopper configured to reciprocate within the hollow housing, the stopper comprising: a piston head, an extended stem coupled to the piston head; and a spring extending along the stem to engage the piston head to bias the piston head away from the stem valve seat so as to form a gap between the stem valve seat and the stem when a first pressure on the piston head provides an opposing force on the piston head...