The two patents featured here both incorporate a needle-feed system to advance the fabric being sewn. However, only the later Oliver patent includes a stitch length adjustment feature, actuated by means of a variable-height needle guide hole.

The first illustration shows A.W.Leader's May 1887 design. This UK patent became the basis for the miniature pressed metal-constructed "Pixie" machine.
A centrally located crank handle turns a rigid connecting rod to power both top and bottom drive shafts. This simple engineering solution, at a stroke, dispensed with the need for any gearing, chains or bands. The patent also envisaged a needle of extraordinary length and complexity. Production considerations obviously played a part in the substitution of this for a more standard needle, held within a suitable carrier.

The second illustration dates from June 1887 and was initiated by W.S.Oliver of Middlesex, England. The subsequently manufactured machine was constructed in cast iron with many brass fittings. The top shaft had a direct hand crank drive and a chain was used to transmit motion from top to bottom shafts.
The machine came supplied with a table clamp for stability in use.