A canvas cover launching device to prevent crimps on the canvas and achieve flattening effect on the canvas, having a frame and a mounting rack on one side, a hydraulic control valve operated by control levers is on the mounting rack. Two driving plastic rollers and a surface smoothening plastic roller are rotatably connected to the frame from inside to outside of the frame sequentially; corresponding ends of the two driving plastic rollers on a same side are connected to a transmission component enabling the two driving plastic rollers to rotate towards the same direction. A synchronous transmission gearbox is provided to connect corresponding ends on a same side of the surface smoothening plastic roller and one of the two driving plastic rollers more proximal to the surface smoothening plastic roller. Hooked plates are symmetrically provided on two ends of the surface smoothening plastic roller respectively.

A canvas cover launching device to prevent crimps on the canvas and achieve flattening effect on the canvas, having a frame and a mounting rack on one side, a hydraulic control valve operated by control levers is on the mounting rack. Two driving plastic rollers and a surface smoothening plastic roller are rotatably connected to the frame from inside to outside of the frame sequentially; corresponding ends of the two driving plastic rollers on a same side are connected to a transmission component enabling the two driving plastic rollers to rotate towards the same direction. A synchronous transmission gearbox is provided to connect corresponding ends on a same side of the surface smoothening plastic roller and one of the two driving plastic rollers more proximal to the surface smoothening plastic roller. Hooked plates are symmetrically provided on two ends of the surface smoothening plastic roller respectively.

A device for providing a material band, including: an unwinding device for unwinding a material band, having two holders for receiving a respective roll of the material band, both holders being movable from a non-working position, in which a roll is received, and a working position, in which the roll is unwound; a transport device, downstream of the unwinding device, for the unwound material strip; a device for connecting a rear end of the unwound material band to a front end of the material band to be unwound; a position detection device including a sensor device for detecting sensor information which describes the position of the strip material in the holders, and a control device for detecting position information based on the sensor information. The position of the strip material to be unwound relative to the unwound strip material can be aligned as a function of the position information. The sensor information can be detected by the sensor device during the movement of the holders from the non-working position into the working position and the control device determines the position information and controls an actuator for moving the respective holder transversely to the transport direction of the transport device as a function of the position information so that the respective holder is positioned at the end of the movement into the working position so that the end of the material band to be unwound is aligned with the end of the un-wound material band.

A device for providing a material band, including: an unwinding device for unwinding a material band, having two holders for receiving a respective roll of the material band, both holders being movable from a non-working position, in which a roll is received, and a working position, in which the roll is unwound; a transport device, downstream of the unwinding device, for the unwound material strip; a device for connecting a rear end of the unwound material band to a front end of the material band to be unwound; a position detection device including a sensor device for detecting sensor information which describes the position of the strip material in the holders, and a control device for detecting position information based on the sensor information. The position of the strip material to be unwound relative to the unwound strip material can be aligned as a function of the position information. The sensor information can be detected by the sensor device during the movement of the holders from the non-working position into the working position and the control device determines the position information and controls an actuator for moving the respective holder transversely to the transport direction of the transport device as a function of the position information so that the respective holder is positioned at the end of the movement into the working position so that the end of the material band to be unwound is aligned with the end of the un-wound material band.