SEWING MACHINE

A sewing machine which in the preferred embodiment includes a hinged stretch bar regulatably biased for applying pressure against a fabric being fed through centralizing slots in a vertical face plate, the bar having an angular side serving to centralize the strip fabric within the slots such that the fabric is fed along a central line extending longitudinally through the fabric across the horizontal platen plate beneath the needle mechanism, the bar being also laterally adjustable and the slots being laterally adjustable for modifying or correcting the central feed line beneath the needle mechanism, the adjusting means including an adjustable nut having female threads matedly mounted on a threaded male projection extending through the biasing spring for controlling biasing pressure against the stretcher arm and additionally the regulating means including an extendable shaft means for shortening or lengthening the leverage by axial movement of the shaft, and as a part of the control of automatically moving the fabric across the plate in the centralized position at a proper rate of movement together with reduced variations in movement of the needle shaft, there is included between a driving cam rotatably mounted on an off-set portion of a driving cam and at an opposite end the mechanism reciprocally driving the toothed feed dog for advancing the fabric beneath the needle, is an adjustable shaft axially adjustable by regulation of a nut around the adjustable shaft, and the variations in needle reciprocation and depth of penetration being reduced by an adjustable pivot axis and by the lever pivoted on that axis being connected at its terminal end to a drive shaft which is centrally flexible and which at the terminal end connected with the pivoted lever mounted in a ball socket for free multi-directional movement and the other end of the flexible drive shaft being mounted for reciprocal axial movement on ball bearings around an off-set portion of a main rotatable drive shaft, undesirable variations in the reciprocating movement of finger and spreader hooks being reduced by replacing the meshing gears between a primary drive shaft and a secondary drive shaft with a belt having along its inner surface a plurality of treads meshable with corresponding teeth on each of the opposing toothed wheels on the respective shafts.