Patent ID: 7568440
Filing Date: 2009-08-04
Classification: D05B

Abstract:
1. A threading device of a sewing machine having at least three needles which are two-dimensionally arranged in horizontal directions, wherein the threading device is operable to thread the respective needles, the threading device comprising: a threading hook operable to insert a thread into an eye of each of the needles by entering the eye by a forward movement and catching the thread by a rearward movement; a threading shaft holding the threading hook; a threading operation inputting mechanism from which a thread inserting movement is given to the threading hook via the threading shaft; a first supporting mechanism supporting the threading shaft so as to be movable in a first direction in a horizontal plane; a second supporting mechanism supporting the threading shaft so as to be movable in a second direction in the in horizontal plane; and a positioning mechanism which, when operated, moves the threading shaft along a path corresponding to an arrangement of each of the needles, wherein the positioning mechanism comprises: a movement operating portion which, when operated, carries out a positional switching toward the respective needles; a first cam mechanism from which a movement in the first direction is given to the threading shaft in accordance with an operation of the movement operating portion; a second cam mechanism from which a movement in the second direction is given to the threading shaft in accordance with the operation of the movement operating portion; and a coupling mechanism operable to combine the movements in the first and second directions from the first and second cam mechanisms and to transmit the combined movements to the threading shaft in accordance with the operation of the movement operating portion, wherein the threading shaft is sequentially moved to positions corresponding to the arrangement of each of the needles in the horizontal directions in accordance with the operation of the movement operating portion.