< Topic >This invention a retracting state where it is stabilized, designates that the retractor which can be implemented with little manipulation is offered as purpose.SolutionsAs slide it is installed by the longitudinal direction possibly the extending where both sides of median fixed part 30a and median fixed part 30a extend respectively Out arm 30b and extending Out vis-a-vis arm, 30b the retracting it allows the plastic deformation of the surface inner split direction Fh in the virtual plane surface F which the retractor which is formed with the supporter 40 who supports 50, vis-a-vis the deformation load which extending Out the deform by flection can point to arm 30b, median fixed part 30a and extending Out is formed in arm 30b, it consisted the compound plastic deformation component which regulates the deformation of direction Fv outside the surface.< Choice figure >Drawing 1【課題】この発明は、安定した開創状態を、少ない操作で実現できる開創器を提供することを目的とする。【解決手段】中央固定部30aと、中央固定部30aの両側のそれぞれに延びる延出アーム部30bと、延出アーム部30bに対して長手方向にスライド可能に装着され、開創鈎50を支持する鈎支持部40とで構成する開創器を、延出アーム部30bを、屈曲変形させる変形負荷に対して、中央固定部30a及び延出アーム部30bで構成する仮想平面Fにおける面内方向Fhの塑性変形を許容するとともに、面外方向Fvの変形を規制する複合塑性変形部材で構成した。【選択図】図1
