Material shaft cone top device with safety bracket and printing machine

The utility model provides a material shaft cone top device with a safety bracket, which belongs to the technical field of printing machines and comprises a rotary arm, a material shaft cone top device and a safety bracket, the material roll comprises an air expansion shaft, and the air expansion shaft is provided with a second positioning part; the air cylinder is connected with the rotary arm, and the top shaft is connected with the air cylinder; the gear is provided with a connecting sleeve, and the top shaft is connected with the connecting sleeve and can move in the axial direction of the connecting sleeve; and the bracket body is connected with the rotary arm, and the bracket body is provided with a bracket groove. The bracket has the beneficial effects that a material coil supported by a trolley and an air expansion shaft can be erected in the supporting groove of the bracket body during feeding operation, so that the bracket plays a temporary lifting role before being butted with a rotary arm, and mea