Automatic hemming apparatus

Claim 2

An automatic hemming apparatus comprising a sewing machine having hem forming means thereon for forming an intergral blindstitch hem on a tubular workpiece, said hem forming means including a needle and a cloth plate, a hem folding mechanism for folding an edge portion only of a tubular workpiece into an Sshaped fold and disposed in cooperating overlying relation to said cloth plate in advance of said needle and generally in alignment therewith, a prefolder for receiving a workpiece on which an integral hem is to be formed disposed in advance of said hem folding mechanism, and material guide means for cooperating with said prefolder to guide material into cooperating relationship with said prefolder, said material guide being in the form of a clamp cooperating with a material engaging and supporting plate, said hem folding mechanism including relatively movable hem folding members and actuator means therefor, and said clamp has separate actuator means, and control means for effecting the operation in unison of both said actuator means to selectively fold and release material.

Claim 3

An automatic hemming apparatus comprising a sewing machine having hem forming means thereon for forming an integral hem on a workpiece, said hem forming means including a needle and a cloth plate, a hem folding mechanism for folding an edge portion only of a workpiece and disposed in cooperating overlying relation to said cloth plate in advance of said needle and generally in alignment therewith, a prefolder for receiving a workpiece on which an integral hem is to be formed disposed in advance of said hem folding mechanism, and material guide means for cooperating with said prefolder to guide material into cooperating relationship with said prefolder, said material guide means being in the form of a combined prefolder and guide plate cooperating with a material engaging and supporting plate, and actuator means for selectively positioning said combined prefolder and guide plate relative to said material engaging and supporting plate to apply a light drag on material to effect the guiding of material.

Claim 4

An automatic hemming apparatus comprising a sewing machine having hem forming means thereon for forming an integral hem on a workpiece, said hem forming means including a needle and a cloth plate, a hem folding mechanism for folding an edge portion only of a workpiece and disposed in cooperating overlying relation to said cloth plate in advance of said needle and generally in alignment therewith, a prefolder for receiving a workpiece on which an integral hem is to be formed disposed in advance of said hem folding mechanism, and material guide means for cooperating with said prefolder to guide material into cooperating relationship with said prefolder, said material guide means being in the form of a combined prefolder and guide plate cooperating with a material engaging and supporting plate, and actuator means for selectively positioning said combined prefolder and guide plate relative to said material engaging and supporting plate to apply a light drag on material to effect the guiding of material.

Claim 5

The automatic hemming apparatus of claim 2 wherein said combined prefolder and guide plate has a beveled edge disposed in acute angular relation to the normal path of material thereover.

Claim 6

An automatic hemming apparatus comprising a sewing machine having hem forming means thereon for forming an integraL hem on a workpiece, said hem forming means including a needle and a cloth plate, a hem folding mechanism for folding an edge portion only of a workpiece and disposed in cooperating overlying relation to said cloth plate in advance of said needle and generally in alignment therewith, a prefolder for receiving a workpiece on which an integral hem is to be formed disposed in advance of said hem folding mechanism, and material guide means for cooperating with said prefolder to guide material into cooperating relationship with said prefolder, said material guide means being in the form of a combined prefolder and guide plate cooperating with a material engaging and supporting plate, and an uncurler disposed in advance of said combined prefolder and guide plate.

Claim 7

An automatic hemming apparatus comprising a sewing machine having hem forming means thereon for forming an integraL hem on a workpiece, said hem forming means including a needle and a cloth plate, a hem folding mechanism for folding an edge portion only of a workpiece and disposed in cooperating overlying relation to said cloth plate in advance of said needle and generally in alignment therewith, a prefolder for receiving a workpiece on which an integral hem is to be formed disposed in advance of said hem folding mechanism, and material guide means for cooperating with said prefolder to guide material into cooperating relationship with said prefolder, said material guide means being in the form of a combined prefolder and guide plate cooperating with a material engaging and supporting plate, and an uncurler disposed in advance of said combined prefolder and guide plate.

Claim 8

The automatic hemming apparatus of claim 4 together with a second uncurler disposed downstream of said first mentioned uncurler and generally in cooperative relation with said combined prefolder and guide plate.

Claim 9

The automatic hemming apparatus of claim 5 wherein said combined prefolder and guide plate and said first and second uncurlers are all mounted on a support plate mounted separate and apart from said material engaging and supporting plate and being positioned by said support plate.

Claim 10

The automatic hemming apparatus of claim 6 wherein said support plate is in the form of a pivot plate mounted for pivotal movement, and means for selectively positioning said pivot plate.

Claim 11

The automatic hemming apparatus of claim 5 wherein said second uncurler is fixedly positioned relative to said combined prefolder and guide plate, and said first mentioned uncurler has means movably mounting the same relative to said combined prefolder and guide plate.

Claim 12

An automatic hemming apparatus comprising a sewing machine having hem forming means thereon for forming an integral hem on a workpiece, said hem forming means including a needle and a cloth plate, a hem folding mechanism for folding an edge portion only of a workpiece and disposed in cooperating overlying relation to said cloth plate in advance of said needle and generally in alignment therewith, a prefolder for receiving a workpiece on which an integral hem is to be formed disposed in advance of said hem folding mechanism, and material guide means for cooperating with said prefolder to guide material into cooperating relationship with said prefolder, a sewn hem detector positioned in the path of material advancing towards said needle, a material ejector disposed adjacent the path of material moving towards said needle for moving material being hemmed laterally away from said needle to terminate a hem stitching operation, and control means actuated by said detector for actuating said material ejector.

Claim 13

An automatic hemming apparatus comprising a sewing machine having hem forming means thereon for forming an integral hem on a workpiece, said hem forming means including a needle and a cloth plate, a hem folding mechanism for folding an edge portion only of a workpiece and disposed in cooperating overlying relation to said cloth plate in advance of said needle and generally in alignment therewith, a prefolder for receiving a workpiece on which an integral hem is to be formed disposed in advance of said hem folding mechanism, and material guide means for cooperating with said prefolder to guide material into cooperating relationship with said prefolder, a sewn hem detector positioned in the path of material advancing towards said needle, a material ejector disposed adjacent the path of material moving towards said needle for moving material being hemmed laterally away from said needle to terminate a hem stitching operation, and control means actuated by said detector for actuating said material ejector.

Claim 14

The automatic hemming apparatus of claim 9 together with thread chain cutter means mounted on said sewing machine downstream of said needle in the direction of material movement, and said control means being operative for actuating said thread chain cutter means simultaneously with the actuation of said material ejector.

Claim 15

An automatic hemming apparatus comprising a sewing machine having hem forming means thereon for forming an integral hem on a workpiece, said hem forming means including a needle and a cloth plate, a hem folding mechanism for folding an edge portion only of a workpiece and disposed in cooperating overlying relation to said cloth plate in advance of said needle and generally in alignment therewith, a prefolder for receiving a workpiece on which an integral hem is to be formed disposed in advance of said hem folding mechanism, and material guide means for cooperating with said prefolder to guide material into cooperating relationship with said prefolder, a sewn hem detector positioned in the path of material advancing towards said needle, a material ejector disposed adjacent the path of material moving towards said needle for moving material being hemmed laterally away from said needle to terminate a hem stitching operaTion, said hem folding mechanism includes relatively movable hem folding members and actuator means therefor, and control means actuated by said detector for actuating said material ejector and effecting operation of said actuator means to move said hem folding members to a material releasing position.

Claim 16

An automatic hemming apparatus comprising a sewing machine having hem forming means thereon for forming an integral hem on a workpiece, said hem forming means including a needle and a cloth plate, a hem folding mechanism for folding an edge portion only of a workpiece and disposed in cooperating overlying relation to said cloth plate in advance of said needle and generally in alignment therewith, a prefolder for receiving a workpiece on which an integral hem is to be formed disposed in advance of said hem folding mechanism, and material guide means for cooperating with said prefolder to guide material into cooperating relationship with said prefolder, a sewn hem detector positioned in the path of material advancing towards said needle, a material ejector disposed adjacent the path of material moving towards said needle for moving material being hemmed laterally away from said needle to terminate a hem stitching operaTion, said hem folding mechanism includes relatively movable hem folding members and actuator means therefor, and control means actuated by said detector for actuating said material ejector and effecting operation of said actuator means to move said hem folding members to a material releasing position.

Claim 17

The automatic hemming apparatus of claim 11 wherein said control means are parts of a control system including a by-pass control rendering said control means ineffective, and timer means in said by-pass control for rendering said detector inoperative whereby operation of said detector by seams and like projections will not prematurely actuate said control means.

Claim 18

An automatic hemming apparatus comprising a sewing machine having hem forming means thereon for forming an integral hem on a workpiece, said hem forming means including a needle and a cloth plate, a hem folding mechanism for folding an edge portion only of a workpiece and disposed in cooperating overlying relation to said cloth plate in advance of said needle and generally in alignment therewith, a prefolder for receiving a workpiece on which an integral hem is to be formed disposed in advance of said hem folding mechanism, and material guide means for cooperating with said prefolder to guide material into cooperating relationship with said prefolder, said apparatus being particularly adapted for hemming tubular material and including a rotary support cooperable with said cloth plate to support tubular material being hemmed, and a stretch roller remote from said cloth plate and said rotary support, said stretch roller cooperating with said rotary support for maintaining tubular material in a hemable position.

Claim 19

An automatic hemming apparatus comprising a sewing machine having hem forming means thereon for forming an integral hem on a workpiece, said hem forming means including a needle and a cloth plate, a hem folding mechanism for folding an edge portion only of a workpiece and disposed in cooperating overlying relation to said cloth plate in advance of said needle and generally in alignment therewith, a prefolder for receiving a workpiece on which an integral hem is to be formed disposed in advance of said hem folding mechanism, and material guide means for cooperating with said prefolder to guide material into cooperating relationship with said prefolder, said apparatus being particularly adapted for hemming tubular material and including a rotary support cooperable with said cloth plate to support tubular material being hemmed, and a stretch roller remote from said cloth plate and said rotary support, said stretch roller cooperating with said rotary support for maintaining tubular material in a hemable position.

Claim 20

The automatic hemming apparatus of claim 13 wherein said stretch roller has adjustable mounting means for adjusting the operative position of said stretch roller in accordance with the dimension of the tubular material being hemmed.

Claim 21

The automatic hemming apparatus of claim 13 wherein said stretch roller has mounting means for moving said stretch roller to a predetermined position relative to said rotary support wherein all tubular material of the same relative size is stretched to a substantially uniform circumference.

Claim 22

The automatic hemming apparatus of claim 15 wherein an uncurler is disposed along the path of material movement between said rotary support and said stretch roller for eliminating curls in material before the material passes around said stretch roller.

Claim 23

An automatic hemming apparatus comprising a sewing machine having hem forming means thereon for forming an integral hem on a workpiece, said hem forming means including a needle and a cloth plate, a hem folding mechanism for folding an edge portion only of a workpiece and disposed in cooperating overlying relation to said cloth plate in advance of said needle and generally in alignment therewith, a prefolder for receiving a workpiece on which an integral hem is to be formed disposed in advance of said hem folding mechanism, and material guide means for cooperating with said prefolder to guide material into cooperating relationship with said prefolder, said hem folding mechanism including relatively movable folder sections, control means for controlling the operation of said sewing machine, control means connected to said folder sections for opening and closing said hem folding mechanism, and ejector means disposed adjacent the path of material moving towards said needle for moving a material edge portion out of alignment with said needle, detector means positioned in the path of material advancing towards said needle for sensing the end of the material to be stitched; and an automatic control system connected to all of said control means and said ejector means for sequentially moving the edge of material being hemmed away from said needle and for discontinuing the operation of said sewing machine.

Claim 24

An automatic hemming apparatus comprising a sewing machine having hem forming means thereon for forming an integral hem on a workpiece, said hem forming means including a needle and a cloth plate, a hem folding mechanism for folding an edge portion only of a workpiece and disposed in cooperating overlying relation to said cloth plate in advance of said needle and generally in alignment therewith, a prefolder for receiving a workpiece on which an integral hem is to be formed disposed in advance of said hem folding mechanism, and material guide means for cooperating with said prefolder to guide material into cooperating relationship with said prefolder, said hem folding mechanism including relatively movable folder sections, control means for controlling the operation of said sewing machine, control means connected to said folder sections for opening and closing said hem folding mechanism, and ejector means disposed adjacent the path of material moving towards said needle for moving a material edge portion out of alignment with said needle, detector means positioned in the path of material advancing towards said needle for sensing the end of the material to be stitched; and an automatic control system connected to all of said control means and said ejector means for sequentially moving the edge of material being hemmed away from said needle and for discontinuing the operation of said sewing machine.

Claim 25

The automatic hemming apparatus of claim 17 wherein said automatic control system includes adjustablE time delay means for accurately timing the actuation of said ejector means and said control means.

Claim 26

The automatic hemming apparatus of claim 18 wherein said hem folding mechanism includes two separately positionable folder sections, and said control system includes means for moving said folder sections to open positions in timed sequence.

Claim 27

The automatic hemming apparatus of claim 18 wherein said hem folding mechanism includes two separately positionable folder sections, and said automatic control system including means for first moving one of said folder sections to an open position, means for next moving the other of said folder sections to an open position, then actuating said ejector means to lead material away from said needle, and then discontinue the operation of said sewing machine.

Claim 28

The automatic hemming apparatus of claim 20 wherein said guide means includes a control device operable after the movement of said one folder section to an open position to release material being hemmed.

Claim 29

The automatic hemming apparatus of claim 20 wherein said time delay means includes a pair of sequentially operable timers.

Claim 30

The automatic hemming apparatus of claim 20 wherein said time delay means includes a pair of sequentially operable timers, and one timing circuit.

Claim 31

The automatic hemming apparatus of claim 20 wherein said time delay means includes a pair of sequentially operable timers, and three sequentially operable delay devices.