US3906878A

US3906878A - Hemming method and apparatus

Info

Publication number: US3906878A
Application number: US442733A
Authority: US
Inventors: Perry E Burton
Original assignee: Individual
Current assignee: SEW SIMPLE SYSTEMS Inc A CORP OF
Priority date: 1974-02-15
Filing date: 1974-02-15
Publication date: 1975-09-23
Anticipated expiration: 1992-09-23

Abstract

Cloth lengths are moved along a path by a conveyor belt with an edge of the cloth to be hemmed extending along the path. A stationary fold guide turns the edge portion of the cloth lengths to form a first hem. The lower flight of an endless band moves through the stationary fold guide and emerges from the guide on top of the fold in the hem. A wheel is driven at varying speeds and in unison with the band take up sheave and exerts control on the advancement and retarding of the first fold in the hem. The first fold is moved with the conveyor belt into a second hemmer, and the second hemmer folds both the first hem and the conveyor belt over to form the double fold hem. The folded portion of the belt is allowed to unfold and the double fold hem is maintained in the edge portion of the cloth by a double band system which includes one band moving on the top of the double fold hem and a second band moving on the body of the cloth adjacent the double fold hem, and a sewing machine sews the double fold hem closed between the moving bands.

Description

United States Patent 1 Burton [451 Sept. 23, 1975 1 HEMMING METHOD AND APPARATUS [76] Inventor: Perry E. Burton, PO. Box 68,

Fountain Inn, S.C. 29644 [22] Filed: Feb. 15, 1974 [21] Appl. No.: 442,733

[52] U.S. Cl. 112/423; 112/262; 1l2/l2l.29;

226/195 [51] Int. Cl. 1332B 7/08 [58] Field of Search 112/203, 262, 141, 147,

Frydryk l12/l2l.15 Burton ..1l2/l21.12

Primary ExaminerRichard J. Scanlan, Jr. U Attorney, Agent, or Firm-Jones, Thomas & Askew [57] ABSTRACT Cloth lengths are moved along a path by a conveyor belt with an edge of the cloth to be hemmed extending along the path. A stationary fold guide turns the edge portion of the cloth lengths to form a first hem. The lower flight of an endless band moves through the stationary fold guide and emerges from the guide on top of the fold in the hem. A wheel is driven at varying speeds and in unison with the band take up sheave and exerts control on the advancement and retarding of the first fold in the hem. The first fold is moved with the conveyor belt into a second hemmer, and the second hemmer folds both the first hem and the conveyor belt over to form the double fold hem. The folded portion of the belt is allowed to unfold and the double fold hem is maintained in the edge portion of the cloth by a double band system which includes one band moving on the top of the double fold hem and a second band moving on the body of the cloth adjacent the double fold hem, and a sewing machine sews the double fold hem closed between the moving bands.

18 Claims, 12 Drawing Figures US Patent Sept. 23,1975 Sheet 1 of2 3,906,878

mm a 0 W US Patent Sept. 23,1975 Sheet 2 m2 3,906,878

HEMMING METHOD AND APPARATUS BACKGROUND OFUTHE INVENTION In the manufacture of cloth lengths, such as towels and other cloth lengths that include hemmed ends, the cloth lengths are usually manufactured by cutting a long length of cloth in predetermined lengths, and the cut ends of the cloth lengths are folded over and sewn in a hem to prevent the hem from raveling and to form an attractive edge.

Hemming towels is becoming more difficult as more and more towels are being woven in multiple widths on larger looms. This requires cutting apart and prehemming the normally selvaged edge. Although many attempts have been made in an effort to automatically form hems in cloth lengths, only a few attempts have been considered commercially successful, and most of the attempts have failed when relatively small hems are to be formed in relatively bulky materials, such as the typically small hems in towels or other objects fabricated from similar materials. As the hem gets smaller and the thickness of the material increases, it is more difficult to automatically form the hem. Moreover, while single fold hems can be formed in some materials, it is much more difficult to automatically form a double fold hem.

In the folding of the edge portions of lengths of material to form double fold hems, it is desirable to form the ends of the hems without having the folded over portions of the hem extend beyond the body of the length of material. The portion of a malformed hem that protrudes beyond the body of the length of the cloth is called hang out" or a dog ear, and the cloth lengths having this feature are considered to be undesirable and are sometimes considered as seconds and sold at a discount.

At the present time, most double fold hems formed in towels and similar relatively thick products are created by hand, by having a worker roll the edge portion of a length of material to form a double fold hem, and feed the hem by hand through a sewing machine. The worker must be careful to properly roll the hem,making sure that no dog ears" appear in either the leading or trailing end of the hem. This requires extensive practice and training for the worker and the speed of operation of the worker is relatively slow. Moreover, the product formed by hand frequently includes a rainbow or a curved and wavey edge in the hem.

SUMMARY OF THE INVENTION Briefly described, the present invention comprises a hemming method and apparatus wherein double fold hems are automatically formed in the edge portions of a series of cloth lengths without requiring a worker to roll the edge portions of the cloth lengths into hems or sew the hems closed. An operator, or possibly a mechanical feeding device, feeds a series of cloth lengths onto a conveyor belt system, and an edge portion of each cloth length is first rolled over onto the body of the cloth length. The movement of the leading portion of the first fold in the hem is retarded to allow the body of the cloth length to move ahead of the leading end of the hem and the remaining portion of the first fold in the hem is advanced ahead of the body of the cloth length to pull the ends of the first fold inwardly at both its leading and trailing ends so that no hang out or dog car" will be present at the leadingend or trailing end of the finished hem. The first fold and the conveyor belt beneath the first fold are folded over onto the body of the cloth lengths to form a. double fold hem, and the fold in the conveyor belt is subsequently allowed to unfold. A double band system engages the edge portion of the cloth length, with one band moving into engagement with the double fold and along the path of the hem and the other band moving into engagement with the body of the cloth length at a position adjacent the hem and along the path of the hem, and a sewing machine functions to sew through the hem between the bands in the double band system.

Thus, it is an object of the present invention to provide a method and apparatus for automatically forming hems in the edge portions of a series of cloth lengths as the cloth lengths move along a predetermined path.

Another object of this invention is to provide a method and apparatus for forming hems in cloth lengths which increases productivity, forms a uniform product, and which is simple to operate.

Other objects, features and advantages of the present invention will become apparent upon reading the following specification, when taken in conjunction with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a schematic perspective illustration of the hemmer.

FIG. 2 is a detail perspective illustration of a portion of the hemmer.

FIGS. 3, 4, 5, 6, 7, 8, 9, 10, and 11 are schematic detail illustrations of a cloth length as it progressively moves through the hemmer.

FIG. 12 is a side cross sectional illustration of the cutting apparatus.

DETAILED DESCRIPTION Referring now in more detail] to the drawing, in which like numerals indicate like parts throughout the several views, FIG. 1 illustrates apparatus 10 for forming hems in the edge portion of a series of cloth lengths, which includes a working table 11, a feed table 12, hemmer 13, and stacker l4. Feed table 12 is positioned so that its upper surface is approximately at the same height as the upper surface of working, table 11. A wall 15 is formed at one edge of feed table 12 and functions as a bench mark against which a worker or possibly an automatic feeding machine places the edges of cloth lengths 16. The wall 15 is located so that it will guide the edges of the cloth lengths into proper alignment with hemmer 13 on working table 11.

Working table 11 includes a plurality of conveyor belts or tapes 18 which are movable along the upper surface of the working table in the direction indicated by arrows 19. As many conveyor belts as needed may be employed. The hemmer 13 includes a folding belt 20 which is also movable along the upper surface of working table 11 in a path parallel to the paths of movement of the conveyor belts 19. Folding belt 20 moves at the same velocity as the conveyor belts 19. but folding belt 20 does not move across the entire length of working table 11. Conveyor belts l9 and folding belt 20 move over conveyor rollers 21 at the ends of their upper flights and the belt driving mechanisminot shown) drives the belts in a conventional manner.

A plurality of presser straps 2-3 are supported by sup port bar 24, and support bar 24 is suspended over working table 11. Pneumatic ram 25 functions to oscillate support bar 24 so that the presser straps 23 are movable toward and away from conveyor belts 19. Photoelectric cell 26 is located in working table 11 and functions to detect the leading end of a length of material 16 as the length of material is moved onto the working table 11 from feed table 12. A pneumatic control circuit (not shown) responds to photoelectric cell 26 and feeds a charge of compressed air to pneumatic ram 25, causing the plurality of presser straps 23 to oscillate downwardly toward the conveyor belts 19 and urge the lengths of material to make positive contact with the top surfaces of the conveyor belts. The coefficient of friction of the conveyor belts 19 as well as folding belt 20 is higher than the coefficient of friction of the bottom surfaces of pressure straps 23 so that the cloth lengths follow the movement of the conveyor belt. If desired, more than one series of presser straps 23 can be used along the lengths of the working table. Also, the width of the conveyor belts can be increased so as to provide more moving surface across the working table.

Hemmer 13 includes a first fold hemmer 27 at a first hemming station, a second fold hemmer 28 at a second hemming station, and guide means 29. First fold hemmer 27 is positioned adjacent folding belt 20 and includes stationary strap 30 which is supported from the surface of working table 11 in a cantilever arrangement. Stationary hemming means 31 includes a first inwardly converging concave guide 32 and a second similar inwardly converging concave guide 33. Stationary strap 30 extends inwardly into the first guide 32, and as the edge portion 34 of the cloth length 16 moves into first guide 32, it is folded over strap 30. If the cloth is relatively stiff, the cloth tends to be broken or creased over the stationary strap 30. Second guide 33 continues the curvature of first guide 32.

A continuous band 35 is mounted on a pair of rotating

sheaves

36 and 37. The sheaves are arranged to rotate in the directions indicated by

arrows

38 and 39, to move continuous band 35 in the direction indicated by arrow 40. The lower flight 41 of continuous band 35 moves from sheave 36 into the space 42 formed between the first and

second guides

32 and 33, so as to move in the confines of second guide 33 toward sheave 37, where the lower flight is taken up by the sheave. Lower flight 41 is angled inwardly toward the edge portion 34 of the cloth lengths 16 from sheave 36 until it is received in second guide 33, whereupon it makes contact with the moving edge portion 34 of the cloth length. Since the edge portion 34 of the cloth length is at least partially prefolded by first guide 32, the lower flight 41 of the band engages the top surface of the fold or hem and tends to hold the fold closed and out of significant drag or frictional contact with the inner surface of second guide 33. 3

Wheel member 44 is positioned in si'de-by-side relationship with respect to sheave 37 and is arranged to rotate in unison with sheave 37. Wheel member 44 includes a resilient tread 45, and the tread is positioned so that it engages the now folded over edge portion 34 of the cloth length at a position spaced from the fold in the cloth length.

Guide rod 47 is mounted on support bar 48 and is supported from the surface of working table 11. Guide rod 47 extends downwardly over the terminal end of second guide 33 and from second guide 33 between sheave 37 and wheel member 44, and then beyond wheel member 44 toward the second fold hemmer 28.

As is illustrated in FIG. 1, drive means 50 is arranged to rotate wheel member 44 and sheave 37 of first fold hemmer 27. Drive means 50 includes variable speed transmission 51 which is connected to the conveyor belt drive system (not shown), driving chain 52, bearing 53, drive shaft 54, and control ram 55. From the illustration of FIG. 1 it should be obvious that variable speed transmission will function to drive wheel member 44 and sheave 37. Variable speed transmission includes control lever 56 which is movable under the influence of control ram 55. Adjustable lever limit screws 57 are located at the ends of the arc of the lever movement and can be rotated to vary the length of the arc of lever movement. Photoelectric cell 58 is located in working table 11 adjacent wheel member 44, and photoelectric cell 58 functions to control the flow of pressurized air to and from control ram 55. The arrangement of the control system (not shown) is such that when photoelectric cell 58 detects the leading edge of a cloth length moving across working table 11, control ram oscillates control arm 56 of variable speed transmission 51 so as to slow the rotational velocity of wheel member 44 and sheave 37. The control system allows control ram 55 to slowly move control arm 56 back to its original position so that wheel means 44 and sheave 37 increase their rotational velocity and peripheral velocity of band 35 and tread 45.

Second fold hemmer 28 includes stationary hemming means 60 which initially includes a folded over or C- shaped entrance 61, and the entire folded over portion is progressively folded over again so that by the time the end of the stationary hemming means 60 is reached, the end configuration is approximately e-shaped. Folding belt 20 enters the second stationary hemming means 60 with the cloth lengths, and its edge portion 63 is folded over as the first hem of the cloth length is folded over inside the second stationary hemming means. When the now double folded hem 62 emerges from the second stationary hemming means 60, the edge portion 63 of the folding belt is on top of the double folded hem.

In order to assure that the folded over edge portion 63 of folding belt 20 does not tend to unfold itself and wedge itself out of the second stationary hemming means 60, bearing member 64 rotatably engages the folded over portion 63 of the belt after it emerges from hemming means 60. Bearing member 64 is mounted from the surface of working table 11 and includes support bracket 65 which supports ball bearing 66 with its lower surface in engagement with the folded over portion 63 of the folding belt. After the folded over portion 63 of the belt passes beneath ball bearing 66, it is free to unfold itself and tends to dose. Ski or guide foot 68 is supported by support bracket 65 and is positioned behind ball bearing 66 where it tends to wedge apart folding belt 20 and the double folding hem 62, and to maintain the double fold in the hem as it moves away from the second stationary hemming means 60.

Double band guide system 29 includes a first pair of band sheaves 70 and 71 positioned adjacent ski 68 and a second pair of band sheaves 72 and 73 further along the path of the hem. Apair of

endless bands

74 and 75 extend about the sheaves in the manner illustrated in FIG. 1. Sewing machine 76 is positioned so that its needle 77 operates between

bands

74 and 75. Gearbox 78 functions to rotate the first pair of band sheaves in the direction indicated by arrow 79. Gearbox 78 is driven by the conveyor beltpower means (not shown) The second pair of band sheaves 72 and 73 are supported by bracket 79, and the planes of the bracket sheaves 72 and 73 are tilted so that the

upper flights

80 and 81 move around the enlarged portion of the sewing machine on their return travel to the first pair of band guide sheaves 70 and 71.

Band guide sheave 70 of the first pair of band guide sheaves is positioned so that the lower flight 82 of band 74 is deposited on the main body portion of the cloth lengths adjacent the double fold 62 of the hem, and the lower flight 82 of band 74 guides the inner edge of the double hem toward the sewing station 84. The lower flight 83 of band 75 is deposited by sheave 71 onto the top surface of the double fold hem 62 and functions to keep the hem in its properly folded attitude and urge the hem on toward sewing station 84. When the cloth length and its folded hem 62 reach sewing station 84, the sewing machine 76 functions to sew the hem closed. The needle 77 of the sewing machine operates between the lower flights 82 and 83 of the

continuous bands

74 and 75. After the stitches have been inserted in the double fold hem 62, the second pair of band sheaves 72 and 73 take up the bands from the cloth length and allow the cloth length to move on with conveyor belts 19 toward stacker 14. It will be noted that folding belt 20 moves with the double folded hem out of the second stationary hemming means 60 and then beneath ski 68 and the first pair of band sheaves 70 and 71. As the folding belt moves beyond the first pair of band sheaves, it turns in a downward direction about a conveyor belt roller 21 to begin its return flight. The cloth lengths continue to move with the pair of

bands

74 and 75 from the end of the upper flight of folding belt 20 into sewing station 84.

Photoelectric cells 87:: and 87b are positioned adjacent sewing machine 76 and function to detect the approaching edge ofa cloth length. Photoelectric cell 87b is arranged to detect the leading edge of a cloth length just after it has been received beneath the needle 77 of the sewing machine, and it functions to temporarily interrupt the continuous movements of conveyor belts 19, folding belt 20 and the bands of first fold hemmer 27 and double band guide 29, while allowing sewing machine 76 to continue to run and to form shorter stitches. The sewing machine is commercially available and includes a system for shortening the stitches formed in the hem. Photoelectric cell 8712 actuates a solenoid valve (not shown) which allows airto flow from a source of air pressure to an air actuated ram, and the movement of the ram controls the stitch control lever position of the sewing machine This causes the feed dogs of the sewing machine to move the material in shorter increments, resulting in crowding the stitches in the material. The stitch crowding helps prevent the ravcling of the stitching in the hem. Photoelectric cell 87:! detects the trailing end of a cloth length as it is about to move out from beneath needle 77 of sewing machine 76, and in response thereto the control system again temporarily interrupts conveyor belts 19, folding belt 20, and the bands of first fold hemmer 27 and double band guide 29, so that stitch crowding can take place at the trailing end of the double fold hem 62.

Sewing machine 76 functions to sew a chain link stitch. and after each cloth length passes through the sewing machine, a length of chain link stitching extends between adjacent onesof the cloth lengths. The cutting mechanism is located in working table at a position 86 which is in alignment with the expectant path of travel of the double fold hem '62. An air flow device 88 (FIG. 12) communicates with the cutting apparatus and pulls the chain link stitch extending between adjacent ones of the hemmed cloth lengths down into the opening in the working table, and the cutting apparatus cuts the chain link. Thus, the cloth lengths are free to be stacked individually by stacker 14.

Stacker 14 is conventional in its construction and merely functions to grasp the leading edges of the cloth lengths as they approach the end of working table 11 and shift them to a stack 90 where they can be retrieved manually or by automatic means. Photoelectric cell 91 positioned adjacent the end of working table 11 functions to actuate the control system (not shown) that operates stacker 14.

As is illustrated in FIGS. 3-12, the method of operation of the hemmer causes the edge portion 34 of a cloth length 16 to be received under the stationary strap 30 and bent or broken over the strap by the first inwardly converging concave guide 32. The lower flight of continuous band 35 moves in behind the first guide 32 (FIG. 3) and in front of the second guide 33 so that it emerges in a position generally on top of the first fold 94 in the cloth length. The second guide 33 (FIG. 4) continues to merge inwardly, downwardly and over the first fold 94 and band .35 so that the band tends to hold the first fold 94 out of significant contact with the second guide 33, and band. 35 is urged downwardly with respect to the first fold 94 at the crease 95 in the material. Folding belt 20 contines to move with the length of material, and the arrangement of folding belt 20 and band 35 is such that very little, if any, static surface engages the edge portion of the cloth length as it travels through the second guide 33.

When the first fold 94 emerges from the second guide 33 (FIG. 5) the lower flight of continuous band 35 continues to rest on top of the hem at the crease, and guide rod 47 helps to hold and guide the first fold on toward wheel member 44. Wheel member 44 engages the first fold 94 and its engagement is at a position displaced further away from the creasefl95 than band 35. When the photoelectric cell 58 detects the leading edge of the length of material, the drive means 50 is slowed down so that the tangential velocityof the wheel member 44 is less than the linear velocity of the body of the cloth lengths and the linear velocity of the band member 35 is less than the linear velocity of the body of the cloth lengths. This tends to exert a slight drag on the first fold 94 and to a smaller degree on the portion of the cloth length beneath the first fold with respect to the rest of the cloth length so that the leading end of the first fold 94 and to a smaller extent the leading end of the portion of the cloth length beneath the first fold will be pulled back away from the leading end of the body of the cloth length. Since the folding belt 20 continues to operate at its constant linear velocity, the body of the cloth length will continue to move at a constant velocity, even though the leading end of first fold 94 and the portion of the cloth length beneath the first fold will be moved through the system at a slower speed and there fore be urged rearwardly with respect to the body portion. After the wheel member 44 and continuous band 35 are initially slowed, they are allowed to speed up after the leading end of the cloth length passes the wheel member until the tangential velocity of the wheel member and the linear velocity of the band 35 are greater than the linear velocity of the body portion of the cloth length. This tends to urge the first fold 94 and the portion of the cloth length beneath the first fold forwardly with respect to the body portion of the cloth length, so that the trailing end of the first fold is moved forwardly with respect to the trailing end of the body portion of the cloth length. Thus, no hand out or dog ears will be created by the leading or trailing ends of the first fold 94 of the hem. Since the portion of the cloth length beneath the first fold eventually forms the second fold in the hem, the retarding and the advancing of the edge portion of the cloth length also prevents hang out from being created by the second fold.

After the first fold of the hem emerges from beneath wheel member 44, guide rod 47 continues to hold the fold closed against belt and guide the fold into the mouth of second stationary hemming means 60 (FIG. 6). The second stationary hemming means 60 is formed in a gradual bend from a C-shape over into an e-shape (FIG, 7), and since the folding belt 20 is inserted in the original C-shape of the guide, the folding belt folds over up into the upper portion of the e-shape. Thus, two thicknesses of the hem as well as one thickness of the folding belt 20 pass through the upper portion of the e-shaped end of the second stationary hemming means,

When the cloth length emerges from the second stationary hemming means 60 (FIG. 8), the folded over portion 63 of the folding belt is still on top of the double fold hem, and as the folded over portion 63 emerges from the hemming means, bearing member 64 engages the folded portion of the belt with its ball bearing 66. This assures that the folded over portion 63 of the folding belt will not be unfolded while in the confines of the second stationary hemming means 60. After the folding belt leaves bearing member 64, it is free to unfold from over the double fold hem 62, and ski 68 (FIG. 9) engages the double fold hem 62 and holds it closed as it progresses toward the double band guide 29.

The lower flight of band 74 is guided by its band sheave down into engagement with the body portion of the cloth length 16 adjacent the double fold hem 62, while the lower flight of band 75 is guided by its sheave 71 down into engagement with the double fold hem 62. The

bands

74 and 75, double fold hem 62, and folding belt 20 then move on toward the sewing station.

Folding belt 20 begins its return flight prior to reaching the sewing station, but the lower flights of

bands

74 and 75 move on through the sewing station (FIG. 11) on opposite sides of the needle 77. The presser foot 93 defines

grooves

94 and 95 in its bottom surface for the purpose of guiding the lower flights of

bands

74 and 75 and the double fold hem 62 toward the proper position beneath the sewing needle 77. Needle 77, feed dogs 96 as well as the other components of sewing machine 76 function in the conventional manner to form a chain link stitch through the double fold hem 62. As the hemmed cloth lengths 16 emerge from the sewing machine, they pass over the cutting apparatus 85 (FIG. 12) where a flow of air in a downward direction tends to urge the connecting chain link stitching into the cutter, so as to cut apart the cloth lengths. The cloth lengths are subsequently stacked by the conventional stacker 14.

The material from which the continuous bands 35' and .74 and are fabricated is polyurethane. The elasticity of this material is such that the pair of

bands

74 and 75 will flex enough to allow the feed dogs 96 to control the movement of the double fold hem 62 as it passes through the sewing machine.

While this invention has beendescribed in detail with particular reference to preferred embodiments thereof, it will be understood that variations and modifications can be effected within the spirit and scope of the invention as described hereinbefore and as defined in the appended claims.

I claim:

l. A method of forming folded hems in a web of sheet material comprising passing the sheet material on a moving belt along a path with the edge to be hemmed extending along the path toward a first hemming station, folding the edge portion of the sheet material upwardly and over on the body of the sheet material to form a first hem at the first hemming station, engaging the first hem with a band adjacent the fold in the hem and moving the band with the sheet material along the path, engaging the first hem with a wheel at a position spaced from the fold in the first hem and urging the hem with the wheel along the path toward a second hemming station, engaging the first hem with a stationary guide extending from between the wheel and the band into the second hemming station, folding an edge portion of the moving belt-and the first hem upwardly and over on the body of the sheet material to form a double hem in the second hemming station, unfolding the edge portion of the belt from over the double hem, engaging the double hem with a band and moving the band with the sheet material toward a sewing station, engaging the sheet material with a band adjacent the double hem and moving the band with the sheet material toward the sewing station, and sewing through the double hem at the sewing station,

2. The method of claim 1 and wherein the step of sewing through the double hem at the sewing station comprises sewing between the band engaging the dou ble hem and the band engaging the sheet material adjacent the double hem.

3. The method of claim 1 and wherein the step of engaging the first hern with a wheel comprises rotating the wheel at a first rotational velocity so that its tangential velocity is slower than the linear velocity of the moving belt as the first end portion of the first hem is engaged by the wheel, and increasing the rotational velocity of the wheel until the tangential velocity of the wheel is faster than the linear velocity of the moving belt as the first hem continues to move along the path.

4. A method of forming folded hems in a length of sheet material comprising moving the sheet of material along a path with the edge of the sheet material to be hemmed extending approximately parallel to the path, folding over the portion of the material at the edge onto the body of the material to form a hem, engaging the folded over portion of the hem with a rotating wheel member with the lower periphery of the wheel member moving approximately in the same direction as the .moving folded over portion of the hem, and increasing or. decreasing the speed ofthe wheel member to move the hem forwardly or'rearwardly with respect to the sheet of material. i

5. The method of claim 4 and wherein the step of increasing or decreasing the speed of. the wheel comprises rotating the wheel member at a tangential velocity which is slower than'thelinear velocity of the hem as the hem is first engagedby the wheel member, and increasing the tangential velocity of the wheel-member to a velocity faster than the linear velocity of-the hem ber.

6. In a method of forming "folded hems in the edge portions of sheets of cloth or' the like wherein cloth is moved along a path with theedge to be hemmed extending approximately parallel to the path and the edge portion of the lengthof cloth is moved through a stationary hemmer and folded over in the hemmer, the improvement therein of moving a band member along its length into the stationary hemmer at a position displaced from the cloth entrance to the'stationary hemmer and into contact with the edge portion of the hem in the length of cloth moving through the stationary hemmer to hold the hem folded, and moving the band member and the hem beyond the stationary holder with the band member continuing to hold the hem closed.

7. In a method of forming folded hems in the edge portions of sheets of cloth or the like wherein cloth is moved along a path with the edge to be hemmed extending approximately parallel to the path and the edge portion of the length of cloth is moved through a sta tionary hemmer and folded over in the hemmer, the improvement therein of moving a band member along its length into the stationary hemmer and into contact with the edge portion of the hem in the length of cloth, taking the band up from the hem with a rotating sheave and engaging the hem with a wheel member rotating in unison with the sheave and engaging the hem at a position displaced from the fold in the hem.

8. In a method of forming folded hems in the edge portions of sheets of cloth or the like wherein cloth is moved along a path with the edge to be hemmed extending approximately parallel to the path and the edge portion of the length of cloth is moved through a stationary hemmer and folded over in the hemmer, the im provement therein of moving a band member along its length into the stationary hemmer and into Contact with the edge portion of the hem in the length of cloth, taking the hand up from the hem with a rotating sheave after the band has moved out of the stationary hemmer, engaging the hem with a wheel member positioned beside the sheave, and engaging the hem with a rod member extending from the vicinity of the stationary hemmer and projecting between the band and the wheel member.

9. In a method of forming folded hems in the edge portions of sheets of cloth or the like wherein cloth is moved along a path with the edge to be hemmed extending approximately parallel to the path and the edge as the hem continues to move beneath the wheel-rn'emportion of the length of cloth is moved through a stasheets of cloth are moved along a path with the edge 3 portions to be hemmed extending approximately para] lel to the path and first folds are formed and the first folds are folded over on themselves to form double folds as the sheets of cloth move along the path, the im- 'fvancingthe movement of the subsequent portion of the first fold in each sheet of cloth with respect to the body of the sheet of cloth.

11. The method'of claim 10 and wherein the steps of retarding and advancing the movement of the first fold in each sheet of cloth comprises engaging the first fold with a rotating wheel member and varying the speed of the rotating wheel member.

12. A method of forming folded hems in the edge of sheets of cloth or the like, comprising moving a length of cloth with a conveyor tape along a path with the edge 'of the length of cloth 'to' be hemmed extending approximately parallel to the path, folding an edge portionof the cloth over onto the body of the cloth, folding the folded edge portion of the cloth and a portion of the conveyor tape over the first fold in the cloth to form a double fold in the cloth, unfolding the conveyor tape from about the double fold in the cloth, simultaneously engaging the upper surface of the double fold with a first band moving with the cloth to hold the double fold in the cloth and engaging the upper surface of the cloth adjacent the double'fold with a second band moving with the cloth to guide the double fold toward a sewing station, guiding the conveyor tape away from the cloth and the path while continuing to move the cloth with the first and second bands through the sewing station, and sewing through the double fold in the cloth between the first and second bands.

13. In a method of forming a folded hem in a length of cloth or the like wherein the cloth is moved along a path with the edge to be hemmed extending along the path and the edge of the cloth is folded over on the body of the cloth in the fold of a belt moving with the cloth through a stationary guide, the improvement therein of maintaining the fold in the belt until the belt has moved beyond the stationary guide, unfolding the belt from about the fold in the cloth, guiding the belt away from the cloth, and sewing through the fold in the cloth.

14. An apparatus for forming folded hems in the edge portions of lengths of cloth or the like including means for moving cloth lengths in sequence along a path with the edges to be hemmed extending along the path, and

stationary hemming means positioned at the edge of the path for folding over the edge portion of the cloth lengths and forming a hem, the combination therewith of an endless band member including a flight movable along its length into the stationary hemmer at a position displaced from the cloth entrance to the stationary hemmer and into contact with the upper surface of the hem formed by the stationary hemmer in the cloth lengths.

15. An apparatus for forming folded hems in the edge portions of lengths of cloth or the like including means for moving cloth lengths in sequence along a path with the edges to be hemmed extending along the path, and stationary hemming means positioned at the edge of the path for folding over the edge portion of the cloth lengths and forming a hem, the combination therewith of an endless band member including a flight movable along its length into the stationary hemmer and into contact with the hem in the cloth lengths. a rotatable sheave positioned over the path of the hem for taking up the band, and a wheel member positioned adjacent said sheave and arranged to engage the hem.

16. An apparatus for forming folded hems in the edge portions of lengths of cloth or the like including means for moving cloth lengths in sequence along a path with the edges to be hemmed extending along the path,'and stationary hemming means positioned at the edge of the path for folding over the edge portion of the cloth lengths and forming a hem, the combination therewith of an endless band member including a flight movable along its length into the stationary hemmer and into contact with the hem in the cloth lengths, a rotatable sheave positioned over the path of the hem for taking up the band, a wheel member positioned adjacent said sheave and rotatable in unison with said sheave and arranged to engage the hem, and a rod member extending for engaging the hem as the hem moves from the stationary hemmer to saidwhee] member.

17. The apparatus of claim 14 and further including drive means for moving said endless band member along its length, and means for varying the speed of said drive means.

18. A sheet of cloth or the like including at least one double folded hem manufactured by a process which includes the step of moving the sheet of cloth along a path with the edge portion to be hemmed extending approximately parallel to the path, forming a first fold in the edge portion and folding the first fold over on itself to form a double fold as the sheet of cloth moves along the path, retarding the movement of the leading portion of the first fold with respect to the body of the sheet of cloth and advancing the movement of the subsequent portion of the first fold with respect to the body of the sheet of cloth.

Claims

1. A method of forming folded hems in a web of sheet material comprising passing the sheet material on a moving belt along a path with the edge to be hemmed extending along the path toward a first hemming station, folding the edge portion of the sheet material upwardly and over on the body of the sheet material to form a first hem at the first hemming station, engaging the first hem with a band adjacent the fold in the hem and moving the band with the sheet material along the path, engaging the first hem with a wheel at a position spaced from the fold in the first hem and urging the hem with the wheel along the path toward a second hemming station, engaging the first hem with a stationary guide extending from between the wheel and the band into the second hemming station, folding an edge portion of the moving belt and the first hem upwardly and over on the body of the sheet material to form a double hem in the second hemming station, unfolding the edge portion of the belt from over the double hem, engaging the double hem with a band and moving the band with the sheet material toward a sewing station, engaging the sheet material with a band adjacent the double hem and moving the band with the sheet material toward the sewing station, and sewing through the double hem at the sewing station.

2. The method of claim 1 and wherein the step of sewing through The double hem at the sewing station comprises sewing between the band engaging the double hem and the band engaging the sheet material adjacent the double hem.

3. The method of claim 1 and wherein the step of engaging the first hem with a wheel comprises rotating the wheel at a first rotational velocity so that its tangential velocity is slower than the linear velocity of the moving belt as the first end portion of the first hem is engaged by the wheel, and increasing the rotational velocity of the wheel until the tangential velocity of the wheel is faster than the linear velocity of the moving belt as the first hem continues to move along the path.

4. A method of forming folded hems in a length of sheet material comprising moving the sheet of material along a path with the edge of the sheet material to be hemmed extending approximately parallel to the path, folding over the portion of the material at the edge onto the body of the material to form a hem, engaging the folded over portion of the hem with a rotating wheel member with the lower periphery of the wheel member moving approximately in the same direction as the moving folded over portion of the hem, and increasing or decreasing the speed of the wheel member to move the hem forwardly or rearwardly with respect to the sheet of material.

5. The method of claim 4 and wherein the step of increasing or decreasing the speed of the wheel comprises rotating the wheel member at a tangential velocity which is slower than the linear velocity of the hem as the hem is first engaged by the wheel member, and increasing the tangential velocity of the wheel member to a velocity faster than the linear velocity of the hem as the hem continues to move beneath the wheel member.

6. In a method of forming folded hems in the edge portions of sheets of cloth or the like wherein cloth is moved along a path with the edge to be hemmed extending approximately parallel to the path and the edge portion of the length of cloth is moved through a stationary hemmer and folded over in the hemmer, the improvement therein of moving a band member along its length into the stationary hemmer at a position displaced from the cloth entrance to the stationary hemmer and into contact with the edge portion of the hem in the length of cloth moving through the stationary hemmer to hold the hem folded, and moving the band member and the hem beyond the stationary holder with the band member continuing to hold the hem closed.

7. In a method of forming folded hems in the edge portions of sheets of cloth or the like wherein cloth is moved along a path with the edge to be hemmed extending approximately parallel to the path and the edge portion of the length of cloth is moved through a stationary hemmer and folded over in the hemmer, the improvement therein of moving a band member along its length into the stationary hemmer and into contact with the edge portion of the hem in the length of cloth, taking the band up from the hem with a rotating sheave and engaging the hem with a wheel member rotating in unison with the sheave and engaging the hem at a position displaced from the fold in the hem.

8. In a method of forming folded hems in the edge portions of sheets of cloth or the like wherein cloth is moved along a path with the edge to be hemmed extending approximately parallel to the path and the edge portion of the length of cloth is moved through a stationary hemmer and folded over in the hemmer, the improvement therein of moving a band member along its length into the stationary hemmer and into contact with the edge portion of the hem in the length of cloth, taking the band up from the hem with a rotating sheave after the band has moved out of the stationary hemmer, engaging the hem with a wheel member positioned beside the sheave, and engaging the hem with a rod member extending from the vicinity of the stationary hemmer and projecting between the band and the wheel member.

9. In a method of forming folded hems in the edge portions of sheeTs of cloth or the like wherein cloth is moved along a path with the edge to be hemmed extending approximately parallel to the path and the edge portion of the length of cloth is moved through a stationary hemmer and folded over in the hemmer, the improvement therein of moving a band member along its length into the stationary hemmer and into contact with the edge portion of the hem in the length of cloth, and varying the linear velocity of the band member between velocities greater than and smaller than the linear velocity of the sheet of cloth.

10. In a method of forming double folded hems in the edge portions of sheets of cloth or the like wherein the sheets of cloth are moved along a path with the edge portions to be hemmed extending approximately parallel to the path and first folds are formed and the first folds are folded over on themselves to form double folds as the sheets of cloth move along the path, the improvement comprising retarding the movement of the leading portion of the first folds in each sheet of cloth with respect to the body of the sheet of cloth and advancing the movement of the subsequent portion of the first fold in each sheet of cloth with respect to the body of the sheet of cloth.

11. The method of claim 10 and wherein the steps of retarding and advancing the movement of the first fold in each sheet of cloth comprises engaging the first fold with a rotating wheel member and varying the speed of the rotating wheel member.

12. A method of forming folded hems in the edge of sheets of cloth or the like, comprising moving a length of cloth with a conveyor tape along a path with the edge of the length of cloth to be hemmed extending approximately parallel to the path, folding an edge portion of the cloth over onto the body of the cloth, folding the folded edge portion of the cloth and a portion of the conveyor tape over the first fold in the cloth to form a double fold in the cloth, unfolding the conveyor tape from about the double fold in the cloth, simultaneously engaging the upper surface of the double fold with a first band moving with the cloth to hold the double fold in the cloth and engaging the upper surface of the cloth adjacent the double fold with a second band moving with the cloth to guide the double fold toward a sewing station, guiding the conveyor tape away from the cloth and the path while continuing to move the cloth with the first and second bands through the sewing station, and sewing through the double fold in the cloth between the first and second bands.

14. An apparatus for forming folded hems in the edge portions of lengths of cloth or the like including means for moving cloth lengths in sequence along a path with the edges to be hemmed extending along the path, and stationary hemming means positioned at the edge of the path for folding over the edge portion of the cloth lengths and forming a hem, the combination therewith of an endless band member including a flight movable along its length into the stationary hemmer at a position displaced from the cloth entrance to the stationary hemmer and into contact with the upper surface of the hem formed by the stationary hemmer in the cloth lengths.

15. An apparatus for forming folded hems in the edge portions of lengths of cloth or the like including means for moving cloth lengths in sequence along a path with the edges to be hemmed extending along the path, and stationary hemming means positioned at the edge of the path for folding oVer the edge portion of the cloth lengths and forming a hem, the combination therewith of an endless band member including a flight movable along its length into the stationary hemmer and into contact with the hem in the cloth lengths, a rotatable sheave positioned over the path of the hem for taking up the band, and a wheel member positioned adjacent said sheave and arranged to engage the hem.

16. An apparatus for forming folded hems in the edge portions of lengths of cloth or the like including means for moving cloth lengths in sequence along a path with the edges to be hemmed extending along the path, and stationary hemming means positioned at the edge of the path for folding over the edge portion of the cloth lengths and forming a hem, the combination therewith of an endless band member including a flight movable along its length into the stationary hemmer and into contact with the hem in the cloth lengths, a rotatable sheave positioned over the path of the hem for taking up the band, a wheel member positioned adjacent said sheave and rotatable in unison with said sheave and arranged to engage the hem, and a rod member extending from said stationary hemming means along the path of the hem and between said sheave and wheel member for engaging the hem as the hem moves from the stationary hemmer to said wheel member.