application_number US 71705376 A description referring to fig1 a portion of a sewing machine is illustrated therein in cross section as including a substantially u shaped bed portion 10 having a top cover plate 12 connected thereto a throat plate member 14 is disposed in an opening in the top plate 12 and includes an aperture 16 for permitting the needle 18 to pass therethrough during its end wise reciprocating movement for penetrating a ply or plies of fabric f with a thread for concatenation with a thread from a bobbin to form lock stitches in a manner which will be more fully described hereinafter the mechanism for reciprocating the needle in its end wise motion is well known in the art and therefore only a portion of the mechanism is illustrated herein as including a needle carrier 22 and a needle bar 24 which needle bar is typically connected to a crank mechanism driven by the main shaft of the sewing machine a feed dog mechanism generally illustrated at 26 is also disposed in an opening in the top plate 12 for cooperating with the fabric f in order to feed the same across the surface of the top plate 12 for forming continuous stitches the feed mechanism including.