47 is moved in association with the movement of the belt 49 which is moved in association with the carriage 44 therefore the moving amount of the distal end carriage 47 is determined by the moving amount of the belt 49 which is twice of the moving amount of carriage 44 on the reason as has been already described hereinbefore in connection with the first embodiment of the invention therefore the movement amount of the distal end carriage 47 is twice of the moving amount of the carriage 44 namely provided that the moving amount of the carriage 44 is s the movement amount of the distal end carriage 47 is 2 s as shown in fig1 c the length l is an addition of a maximum moving amount la of the carriage 44 and a maximum moving amount lb of the distal end carriage 47 to the right in the direction y wherein la equals lb in this connection fig9 b shows in detail a part of a toothed 19 which is in mesh with a toothed pulley 15 which may be employed in place of the cord belt 49 and the corresponding pulleys 45 a 45 b further a wire may be used.