changed by means of a clutch having a portion which selectively contacts the clutch portion of either the first or second feed wheel application_number US 20147888 A description the preferred embodiment of the invention will now be described with reference to the accompanying drawings the same numeral references are assigned to the same components throughout the drawings in the figures reference numeral 1 denotes an intermediate shaft as a drive shaft provided at one end thereof is a flywheel 2 connected with a drive source which is not shown via a drive belt and sprockets 3 and 4 are secured on the central portion of the drive shaft 1 the sprocket 3 is connected via a toothed belt 7 with a sprocket 6 which is secured on an arm shaft 5 the sprocket 4 being connected via a toothed belt 10 with a sprocket 9 which is secured on a bottom shaft shaft body 8 at one end thereof with such a construction the arm shaft 5 and the bottom shaft 8 are designed to rotate as the intermediate shaft 1 rotates and one rotation of the arm shaft 5 generates one stroke of a needle n a descending and ascending motion when descending the needle n is accepted into a needle hole mai provided in a work support ma which is provided on the bed of a sewing.