Attachment for embroidering initial letters, patterns and the like in a zigzag sewing machine

Claim 1

An attachment for embroidering initial letters, patterns, and the like, constructed for disengageable securement to the upper surface of the bed plate of a zigzag sewing machine having a vertically reciprocable, laterally oscillatable needle bar carrying a needle, and a vertically displaceable presser bar mounting a presser foot engageable with a cloth work piece, said attachment comprising, in combination, an attachment mounting base securable to the upper surface of said machine bed plate; a relatively elongated substantially rectangular and substantially flat cam plat having a pair of cam grooves extending longitudinally of its under surface; a mounting and guiding structure secured to said mounting base and having first means defining a substantially rectangular cross section and substantially rectilinear guide slot, for a cam plate, extending transversely of said attachment, and second means defining a recess an interlocking member mounted in said recess for limited displacement longitudinally of said attachment and limited oscillation about a substantially vertical axis, said interlocking member having an oscillatable end projecting from said structure toward said needle bar; a pair of cam followers operatively associated with said interlocking member and engageable with respective grooves of a cam plate inserted into said guide slot; a rocking arm mechanism mounted on said structure and including a rocking arm engageable with said needle bar for rocking responsive to reciprocation of said needle bar, and arm means cooperable with said presser bar to lift the presser foot responsive to upper movement of said needle bar; a follower arm operable by said rocking arm mechanism; pawl and ratchet mechanism operable by said follower arm and cooperable with a cam plate inserted into said guide slot to step the cam plate longitudinally of said guide slot; and an embroidery frame secured to the projecting end of said interlocking member for conjoint movement with the latter; said rocking arm mechanism, responsive to retraction of said needle from the work piece and disengagement of the presser foot from the work piece, operating said follower arm to operate said pawl and racket mechanism to advance the cam plate longitudinally of said guide slot; said cam followers reciprocating and oscillating said interlocking member in accordance with the contours of the respective cam grooves to correspondingly reciprocate and oscillate said embroidery frame relative to said needle.