Automatic trouser indexing method and apparatus for belt loop attachment

A method of stitching belt loops onto a waistband of trousers comprising,

• placing an end of the waistband corresponding to where a first waistband loop is to be attached onto a stitching station of a sewing machine,
• stitching a first belt loop at a first belt loop attachment position,
• indexing the trousers by moving the waistband lengthwise through the stitching station by a pulsed motor movement mechanism which is drivingly connected to the trousers, while also detecting a waistband seam,
• counting a predetermined number of pulses after detecting each waistband seam,
• correlating subsequent belt loop attachment positions with a position of a detected seam in accordance with a predetermined setting of the number of required belt loops, and
• incrementally indexing the trousers lengthwise into belt loop attachment positions while stitching a belt loop at each belt loop attachment position.

An apparatus for stitching belt loops onto a waistband of trousers comprising,

• a sewing machine having a sewing machine arm defining a stitching station where belt loops are stitched onto the waistband of trousers,
• an indexer clamp that engages the trousers,
• a stepper motor drivingly connected to said indexer clamp for driving said clamp and moving the waistband of an engaged pair of trousers in one direction lengthwise through the stitching station,
• seam detector means for detecting a seam as the waistband is moved through the stitching station, and
• control means operatively connected to said seam detector means and said stepper motor for 1) receiving signals from said seam detector means indicative of the presence of a seam, 2) correlating the detected position of the seam with the attachment position of belt loops, and 3) controlling the stepper motor to stop when each of successive belt loop attachment positions are moved at the stitching station.

A method of indexing a waistband of trousers into belt loop attachment positions at a stitching station of a sewing machine comprising,

• moving the waistband lengthwise through the stitching station of a sewing machine by a stepper motor and means drivingly engaging the stepper motor and waistband,
• detecting the presence of waistband seams while the waistband moves lengthwise to provide known reference points relative to the position on the waistband where belt loops are to be stitched,
• counting a predetermined number of stepper motor pulses after detecting each waistband seam corresponding to a belt loop attachment position, and
• incrementally stopping waistband movement after a predetermined number of stepper motor pulses have been counted as the waistband moves into succeeding belt loop attachment positions.

An apparatus for indexing a waistband of trousers into belt loop attachment positions at a stitching station of a sewing machine, comprising

• a stepper motor, including means drivingly engaging the stepper motor and waistband for moving the waistband of trousers lengthwise through the stitching station,
• means for detecting the presence of seams while the waistband is moving,
• means for correlating waistband attachment positions for belt loops relative to the detected position of seams, said correlating means including means for counting stepper motor pulses after each detected seam, and
• means for incrementally stopping waistband movement after counting a predetermined number of stepper motor pulses after each detected seam corresponding to belt loop attachment positions for controlling the movement of the waistband through the stitching station for incrementally positioning the belt loop attachment positions at the stitching station for stitching of belt loops onto the waistband.