1. A surgical stapling instrument, comprising: an end effector, comprising: an elongated channel configured to functionally support a surgical cassette with brackets； an Iupor supported on an elongated channel with the ability to move between an open and a closed position in response to the application of opening and closing movements thereto； an emphasis blocking element cooperating with the emphasis to hold the emphasis in an open position when the cassette with brackets is not installed in the elongated channel, and preventing the emphasis from moving to the closed position until the cassette with brackets is installed in the elongated channel. 2. The surgical stapling instrument according to claim 1, wherein the abutment comprises a mounting portion of the abutment supported to rotate on an elongated channel, wherein the abutment locking member is biased into contact with the abutment mounting portion. 3. The surgical stapling instrument according to claim 2, wherein the mounting part of the stop further comprises a pair of opposing stop shoes, which can be moved into the corresponding slot of the shoes in an elongated channel. The surgical stapling instrument according to claim 3, wherein each notch of the stop shoe comprises: a blocking slot for receiving a corresponding stop shoe therein when the surgical cassette with brackets is not installed in the elongated channel； an arcuate slot segment for receiving a corresponding stop shoe into it when the cassette is installed in the elongated channel, so that the corresponding stop shoe can move in the arcuate slot segment when applying a closing movement to the stop. 5. Surgical stapler1. Хирургический сшивающий инструмент, содержащий:концевой эффектор, содержащий:удлиненный канал, выполненный с возможностью функционально поддерживать в себе хирургическую кассету со скобами； иупор, поддерживаемый на удлиненном канале с возможностью перемещения между открытым и закрытым положением в ответ на приложение к нему откр
