Rotary looper for a lockstitch sewing machine

Abstract

A rotary looper for a lockstitch sewing machine, which can receive either a coreless thread package or a thread-wound bobbin. An upper bobbin-housing part is provided with two separate thread-tensioning elements and with respective thread-guide slots associated with them. In this way, the thread withdrawn either from a coreless thread package or a looper-thread bobbin passes over an optimally-shaped thread path on its way to the sewing area, and in both cases, a specifically adapted thread-tensioning force is exerted on the thread withdrawn. Preferably, the front part of the thread supply, in the coreless package or bobbin, can be accommodated in front of the movement path of the sewing needle, whereby the bobbin-housing can accommodate an extra-wide thread supply. An upwardly extended shoulder is provided on the lower part of the bobbin housing, so that the axially widened needle thread loop can slide unimpeded over the axially-extended bobbin-housing upper part. Preferably, there is also an oblique guide surface on the rear of the lower bobbin-housing part for further facilitating the passage of the needle thread loop.

Dependencies are inferred from the claim text.