Backstitch sewing machine - having stationary supports round lower thread bobbin housing, with free play, for looper and upper thread loop

摘要

In a back stitch sewing machine, the housing for the bobbin carrying the lower thread is separated from the looper moving round it, and is supported on its periphery by a number of carriers mounted to the sewing machine frame. The carriers comprise on one side the looper or the shaft of the bobbin housing at its face, and a number of supporting points on the other side. The supporting points are located round the bobbin housing and opposite its narrow side so that all supporting points are stationary against the machine frame and are not moved while the looper goes round the bobbin housing. The relatively simple, reasonably priced structure operates quietly and without faults.