drum b may be located adjacent to the drum a on the shaft 16 an internal drum 46 is rotatably attached to the shaft 16 which internal drum 46 is secured with the drum b the internal drum 46 is further attached with a rotary sprocket wheel 47 which is connected by chain 48 to a second driving sprocket wheel 49 fixed to other end of the drive shaft 44 it will be seen that the rotary sprocket wheel 47 of the second drum b has a diameter relatively larger than that of the rotary sprocket wheel 41 of the first drum a the two driving sprocket wheels 43 and 49 as described and mounted on the drive shaft 44 have the same diameter the second driving sprocket wheel 49 which rotates the second drum b may preferably be provided with a freewheel means not shown a pawl 50 is provided on an outer side of the rotary sprocket wheel 47 of the second drum b which pawl is located opposite to the engaging part 51 of the clutch 45 as above described when the drive shaft 44 is rotated the first and second drums a and b are rotated and at this moment the second drum b is rotated slower than the first drum a thereafter the lengthy cloth band 36 of the lower part of each drum having equal loosening and being dipped in the treating.