Usm Corporation

David J Commander

Peter N Tapner

Robert S Berks

Geoffrey K Collett

John Corbett

Christopher B Martin-Jones

Edric M Brown

Mark S Gilbey

A lockstitch sewing machine has a needle (22) and awl (24) mounted on a common pivot (52) and actuated each by a crank mechanism (40;72), the two mechanisms being mounted on a common crank shaft (38). Each mechanism is constituted by a bell crank lever (44;76); the two levers also being mounted on a common pivot (46). This latter pivot (46) is disposed intermediate the pivot (52) for the needle and awl and the crank shaft (38).

Lockstitch sewing machine

A lockstitch sewing machine has, in addition to stitch forming instrumentalities (22, 24), a needle thread control arrangement (32) by which the tension in the needle thread (T2) is controlled during stitch formation. In addition, said arrangement (32) ensures that each formed stitch is drawn into the body of the workpiece, by pulling on the thread while it remains clamped by thread clamping means (200, 202). This pulling takes place in the early stages of the formation of the next stitch so that, at the end of the machine stitching cycle, the final stitch is not set by this arrangement (32). Instead, electrically actuated stitch setting means (220 to 226) is provided operable in response to an 'end of cycle' signal supplied by control means by which further 'end of cycle' functions (e.g. release of a presser foot (36) and of the thread clamping means (200, 202) are also controlled.

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Milton Keynes, United Kingdom

David J Commander