Abstract: One limb of each loop which is formed by the needle thread in an oscillating hook type sewing machine is temporarily in contact with the loop-engaging member of a braking device whose torsion spring is non-rotatably installed in the hollow mandrel of the hook. The loop-engaging member is turned by successive loops from a starting position, relative to the hook and against the opposition of the spring so that it tensions the loop while the latter is raised by the takeup lever. The spring thereupon rapidly returns the loop-engaging member to its starting position. The loop-engaging member is integral with a loop catcher which intercepts the loop when the latter is cast off the hook and which ensures that the loop comes in contact with the loop-engaging member.

Abstract: An attachment for cutting the edge of a length of material travelling towards a sewing location is mounted on the working or operating surface of a sewing machine. A drive fork is acted upon by a needle bar and drives a movable cutter blade via a drive or control cam carrier. The movable cutter blade is arranged at a blade holder which is pivotable about a pivot axis which is laterally spaced from a cutting plane defined by the movable cutter blade and a fixed cutter blade. A large throughpassage or space for strips separated from the length of material by the cutter blades is formed between the cutting plane and the blade holder.

Abstract: A mechanism for coupling and uncoupling a driven rotatable drive wheel from a rotatable shaft, particularly, the arm shaft of a sewing machine from its associated drive wheel in order to spool up the lower thread, comprises a rotatable shaft which has an annular collar portion which is frictionally engageable by a drive wheel which is freely rotatable on the shaft. The drive wheel is continuously driven from a drive, such as a belt, and it may be urged into engagement with the collar by means of a nut which is threaded onto the end of the shaft. The arrangement includes a stop disc which has a cam surface which is engageable with a stop defined on the nut end face in a recess thereof. The cam surface and the stop define a cam structure which permits rotation of the nut so as to permit frictional engagement of the drive wheel with the shaft collar for driving the shaft and the disengagement thereof by rotation of the nut in a reverse direction.