GB1152086A - Sewing Machines - Google Patents

Abstract

1,152,086. Sewing machines. GENERAL AUTOMATED MACHINERY CORP. 21 Sept., 1966 [24 Oct., 1965], No. 42072/66. Heading D1G. A sewing machine has an attachment for severing tape fed thereto which comprises a knife blade, a pneumatic ram for moving the knife blade into engagement with the tape where it is to be severed, and a pneumatic valve for operating the ram actuable under the influence of means sensitive to a change of pressure at the open end of a tube in the presence of a workpiece. A bracket 28, secured to the head 13 of a sewing machine having a face work-supporting arm 14, supports a pneumatic ram 69 the piston rod of which is spring-biased upwardly and carries a knife blade 76. Energisation of a solenoid valve 142 admits compressed air to ram 69 for lowering knife 76 to cut binding tape 16. During the descent of the piston rod, a cam thereon actuates a microswitch 88 for de-energising valve 142 to allow ascent of the piston rod. A sleeve 96 secured to the end of arm 14, supports a blade for co-operation with knife 76, and a throat plate 98. Arm 14 also supports tape-guiding pins 15 and a folder guide 136 which leads the folded tape under the presser foot 13c. A horizontal slot 30 in bracket 28 accommodates screws 37 which secure in adjusted position vertical tubes 35, 33, 31 aligned in the direction of work feed, the open ends of the tubes being positioned above the upper surface of the throat plate. A plate 112, positioned in an aperture in sleeve 96 and secured to the end of arm 14, has horizontal slot 120 accommodating three screws 119 securing in position vertical tubes 117, 115, 113 which are aligned with the tubes 35, 33, 31 respectively, and the open ends of which are positioned below the upper surface of the throat plate. A cover 95, enclosing the lower part of arm 14, is secured at its upper ends to arm 14 by plates 135 and (138). Compressed air is supplied to the tubes and each vertically aligned pair of tubes is connected to a valve adapted, when an obstruction is positioned between the aligned open ends, to actuate a microswitch. The arrangement is such that when the leading end of a workpiece passes between tubes 35 and 117 the machine automatically starts, when the leading edge passes between tubes 33 and 115 knife 76 descends to sever tape 16 projecting forwardly from the workpiece, and when the trailing end of the workpiece uncovers tubes 31 and 113 knife 76 descends to sever tape 16 projecting rearwardly from the workpiece. In a modification 9, Fig. 16, a horizontal arm (214), secured transversely to the machine bed, is rigid at one end with a gooseneck arm (215) which extends longitudinally of the machine bed and supports the knife-actuating ram, the solenoid pneumatic valve, the microswitch and the tubes 31, 33, 35. A horizontal bar (235), secured to bar (214) and extending longitudinally of the machine bed, supports the fixed knife blade, the throat plate, and the tubes 113, 115, 117.