DE1239923B - Equipment on sewing machines for forming and guiding a double-turned hem - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. α .:

D05b

German class: 52 a -52/04

Number:
File number:
Registration day:
Display day:

P 31940 VII a / 52 a
4th June 1963
May 3, 1967

The invention relates to a device on sewing machines for forming and guiding a double folded hems on textile workpieces with the help of a hem guide and a folding rail.

Double-folded hems are usually made with the help of a hemmer, which consists of a there is a bag-shaped cover plate in front of the stitch formation point is arranged and the edge of a workpiece fed to the stitch formation area folds over twice. In such devices, the edge ίο of the workpiece must be before the start of each hemming process be newly introduced into the moulder. This introduction is cumbersome and time consuming and requires especially with a narrow hem, in addition to some skill of the seamstress, the help pointed tools. This can easily damage the sewing material, but above all the point where the hem begins will be greatly distorted. That has a very detrimental effect on the appearance of the workpiece. In these known hemmer, it is also difficult, the leading edge of the hem flush with the workpiece edge perpendicular to the hem edge. The double turning of the fabric edge is done with the help of the bag-shaped folding sheet attached to the hemmer namely on a relatively short distance. This puts the starting edge of the hem at an angle to the Workpiece edge. This has the consequence that the end edge of the hem also after sewing is not flush with the end edge of the workpiece, but protrudes beyond it and afterwards must be cut off.

Furthermore, a device for machine-forming a double-folded seam on workpieces is known, in which the production of the seam takes place in two phases, namely the edge of a workpiece is first simply folded over when it is at a standstill, a set of laying tools being used one fixed and one on the firmly pressed angle rail and one articulated, the free edge of the workpiece clamped between the angle rails at a distance from the edge edge over the folding bar moving an angle rail and then by passing the simply folded workpiece edge through one in the path of movement of the workpiece arranged conventional bag-shaped hemmer turned over again. The drive device for the set of laying tools, one of which moves in a vertical path and the other in a horizontal path, is very complicated in this device
Leading a double-folded hem

Applicant:

G. M. Pfaff A. G., Kaiserslautern

Named as inventor:

Reinhold Dobner,

Heinrich Berg, Kaiserslautern

and only enables the automatic shaping of a simple hem. In addition, with this device, when the workpiece edge is subsequently turned over again by means of the bag-shaped hemmer during the movement of the workpiece, the disadvantages already described occur which are known and already described in the processing of workpieces with such immovable hemmer.
"Hemmer is already known which is designed to avoid distortion of the fabric and to better introduce the beginning of the hem, with one part of the hemmer being displaceable perpendicular to the hem edge. The beginning of the hem is inserted with the hemmer open and around a folding rail by hand Then the hemmer is closed by moving the movable hemmer part Apart from the laborious and time-consuming handling, hemmer of this type cannot be used for automatic sewing systems.

There are also folding machines known on which double-folded hems on machine Paths can be produced, with the help of extending over the entire width of the workpiece Folding poles that rotate around themselves and each work with a folding slide. With folding machines of this type, this is already located on a web of material by means of swingably mounted grippers The workpiece is peeled off the hemmed longitudinal edges and cut to length with a knife before the start the hem laying process with its two unhemmed edges over the one end with one each Gear provided and each having a folding slot having folding rods to which it is controlled by means of Workpiece clamps is pressed. When the first seam folds are formed, the two are still unhemmed Workpiece edges through the curve

709 578/84

3 4

controlled folding slider in the folding slits the FaItgang runs automatically, the new hem laying mat can

rods pushed in, whereupon the folding slides and direction are also used in sewing transfer lines

the workpiece clamps are in their starting position.

be brought. Another control cam controls over When processing elastic, difficult to

a lever mechanism a rack with which the 5 folding fabrics are evading the first

one of the gears attached to the folding rods, a double envelope around the folding rail

in the immediate and with the other workpiece edge turned over via a or folding tongue

Intermediate wheel is in operative connection. By following the rest of the hem length while shaping

Displacement movement of the rack by a further proposal according to the invention

At a certain amount, the folding bars are prevented by a guide plate, which with the help of springs

set directions rotated by 270 °, whereby the can be moved into a position in which it is at the

The hems on the two workpiece edges are touched by their final first fold-over edge.

received valid form. The work prepared in this way - The guide plate can be attached to the seam layer or seam guide

piece will be hinged to the rer with the help of fabric slides.

Stitch formation areas advanced. With such dimensions, two are designed according to the invention.

work results that can be achieved by machines are indeed satisfied working examples on the basis of drawings

thinking, however, it is only described through one survey. It shows

borrowed constructive effort achieved. The insert Fig. 1 in an overall view with a sewing machine

The machine is also designed for the machining of parts arranged on the head and shown in section

comparatively small workpieces, for example 20 hem laying devices,

Handkerchiefs and napkins, limited. FIG. 2 shows the hem laying device according to FIG. 1 in

Finally, a hem laying device is also available for perspective representation,

Label sewing machines become known in wel- Fig. 3 to 7 schematically with a folding rail

rather by a seam guide working together around a stationary folding rail in different

movable seam layer the laying of one, however, 25 phases of the seam laying process,

only simple hems is made possible. In this Fig. 8 in an overall view another embodiment

known arrangement is used during the lowering form of the hem laying device for simultaneous

kens the presser foot via cam-operated counter-hemming of two workpieces,

rod connections driven hem layers only F i g. 9 is a plan view of the fabric support plate of FIG

in one of a vertical and a subsequent sewing machine shown in FIG. 8 with a section

at the end of the existing horizontal section through the arm to line IX-IX,

emotional. However, such a movement is only sufficient for FIG. 10 the in F i g. 8 shown hem laying device

for laying out a simple seam, which in the case of this is shown in perspective,

this device over the entire length of Fig. 11 to 15 schematically each with a FaIt-

Length of the workpiece and when sewing in 35 rails cooperating seam guide in different

this state through the feed tools of the sewing phases of the hem laying process,

machine from which it is in its end position.

delicate hem forming tools is pulled out. plate 1 of the sewing machine one in front of the throat plate 2

In order to avoid the disadvantages described of the known persons (FIG. 2) and the knife gate valve 3 Hem laying devices are located on the invention panel 4 with a recess 5. On the fabric dung The technical problem is based on the mold support plate 1, the arm 6 is placed in which the a double folded hem (similar to arm shaft 7 is mounted, which one end of the handle the previously described hem laying device wheel 8 and the other end carries the arm shaft crank 9, for label sewing machines) by one movement of the seam guide opposite the stationary fold 45 which shines up and down in the needle bar frame 11 to effect. According to the invention, this movable needle bar 12 is connected to its The object is achieved in that the seam guide carries the needle 13 to the lower end. The needle bar shapes of the hem one of the outline shape of the hem frame 11 is around the bolt 14 in the feed line cross-section corresponding quadrilateral movement pivoted around the device. The swivel movements the folding rail is issued. 50 are attached to the arm shaft 7

The size of the hem cross-section can be derived depending on the adjustable feed eccentric 15 and over

Type of workpiece to be machined (e.g. fork 16, oscillating shaft 17 and crank 18

Sheet or a handkerchief) transferred differently to the needle bar frame 11,

be. The beginning edge of the hem is also flush. A housing 20 is located on the head 19 of the sewing machine

to lie with the front edge of the workpiece. When the 55 is attached, the one with a vertical sliding guide 21

The initial part of the seam placed in this way is provided in which an angle bracket 22 is up and down

and the hem guide is movably supported in its end position. The latter has two perpendicular

finds, any length of workpiece can be attached to the slide guide 21 at a distance from one another.

the seam guide through the stitch-forming point panels 23, 24 ordered by train, in the sides of which are horizontal

leads, with the workpiece edge continuously 60 sliding guides 25 are incorporated. In the sliding

By means of a recess 25 together with the folding rail, a support frame 26 is displaceable.

Running-folding guide-forming seam guide stores in the shape of a seam. The support frame 26 has one downward

is folded. protruding arm 27 on which a seam guide

Since the workpiece is fixed in the 28 according to the invention. Two opposing connecting hem laying devices only in the correct position 65 extension webs 29,30 of the support frame 26 are with Nokunter the driven seam guide brought to kenansätze 31, 32 provided with which one on what needs to be done by means of a suitable supply device for the output shaft 33 of a fastening device on the housing 20 can be done, and the seam-laying gear motor 34 between the plates 23,24

5 6

and inside the support frame 26 fixed curve On the head 62 of the sewing machine a housing 72 is disc 35 cooperates to the support frame 26 with a geared motor 73 to move the horizontal. On the output shaft 33, drive shaft 74 in the bore of a bearing shoulder 75 is also a cam disk 36 with an end face of the housing 72 is rotatably mounted. Fastened to the lower, laterally arranged control surface 37, with which end of the output shaft 74 a cam disk 76 fastened to the upper plate 23 is fastened by means of the screw 78, which works together with two control pins 38. By means of one end of surfaces 77 which each occupy 180 ° of the circumference of the curves of a pin 39 fastened to the housing 20 and the other disk 76. Another cam disk at the end of a pin 79 fastened to the bracket 22 is above the cam disk 76 by means of the tension spring 41 acting on the plate 10 screw 80 and has two tracer pin 38 fastened to the end 23 together with the winch-arranged control surfaces 81 The upper end of the cam 79 is held on the surface 37 of the cam 36, which each occupy 180 ° of the kelträger 22 and the support frame 26 with Saumfüh- lower end face of the cam 79. The curve bearing approach 75 at. On the opposite end disk 36 carries on its circumference a switching cam 15 side of the bearing shoulder 75 is an adjusting ring 82 on the 42, which is attached to an output shaft 74 arranged on the plate 23. The output shaft 74 is switch 43 with the switch pin 44 acts. One up to this secured against axial displacement,
In front of the throat plate 2 protruding and because of the better The adjusting ring 82 has on its circumference a stability, hollow folding rail 45 is attached to the cam 83, in whose movement path the switching pins, not shown, are attached to the machine frame. 20 84, 85 of two switches 88, 89 protrude on each

An angle 86, 87 partially fastened to the bearing attachment 75 in FIG. 2 serves as a fabric support

reproduced support plate 46, which are arranged in guides.

of the machine frame (not shown, displaceable). The output shaft 74 is located in the housing 72 on both sides

is arranged. The one support 90, 91 located next to the folding rail 45 is arranged. Each of these carriers

The edge of the support plate 46 can optionally have a longitudinal slot 92 at its upper end

Fixation of the material to be sewn with needles. or 93. Projecting through each of the longitudinal slots 92, 93

In a recess of the insert plate 4 is a bolt 94 or 95 fastened to the housing

Switch 47 is arranged with switch pin 48, which lower ends of the carrier 90, 91 are in on the housing

from the front edge of the platen 46 actuated 72 trained guides 96, 97 perpendicular to

can be. 30 feed direction movably guided. To the one of the

In order to also use elastic materials with the device, the drive shaft 74 facing sides of the carrier 90, 91 are difficult to fold, to be able to edit, scanning cams 98, 99 and 100, 101 are for the the seam guide 28 has two angularly bent control surfaces 77, 81 of the cam disks 76, 79 from bearing tabs 49, 50, in the bores of which the bearings are formed. Springs 102, 103, 104 hold the scanning axis 51 one at the lower end L-shaped formed 35 cams 98, 99, 100, 101 in a force-locking connection Guide plate 52 is arranged. The lead-in edges with the control surfaces 77, 81 of the curve scheiam Guide plates 52 for the sewing material are rounded. ben 76, 79. As a result of the training and A torsion spring arrangement arranged around the bearing axis 51 can support the supports 90, 91, which is attached to one end on the hem guide 28 and a hem guide 105 and 106 respectively at the other ends ends on the baffle 52, exercises on the baffle 40, both limited vertical displacement movement 52 a clockwise torque. gen as well as limited swivel movements around the The bearing axis 51 is implemented by means of bolts 94, 95, which are not shown.

Circlips secured against falling out. Since the on the cloth support plate 60 are two guide spacing between the bearing axis 51 and the lower rails 107, 108 attached, in which one with a Ren end of the baffle 52 just as large as the 45 funnel-shaped recess provided support plate Distance between the bearing axis 51 and the inner 109 is displaceably arranged. The platen side of the bottom of the hem guide 28, the lower 109 actuates in its end position one on the fabric offset Part of the guide plate 52 but parallel to the support plate 60 attached switch 110. On the Aufeiner through the center of the bearing axis 51 going support plate 109 is a straight line by means of a bolt 112 is arranged offset, the guide 50 can articulated clamping frame 111, on which a lever plate 52 is clamped only a limited pivoting movement by 113, which is connected to the arm 61 of the run the bearing axis 51 as a fulcrum. The sewing machine attached stop 114 for tying End positions of the guide plate 52 are in pivoting of the bumper frame 111 together-F i g. 5 and 7 reproduced. works. The fabric clamping frame 111 has on its front

The second exemplary embodiment shows in FIG. 55 the end of two folding rails 115, 116, which extend up to FIG. 8 to 10 extend the new device in connection just before the stitch formation points. In front of the one with a two needle machine with arm up front throat plate 117, through whose slots the toothed thrust. On the fabric support plate 60 of the sewing machine webs of the fabric driven in a known manner, the arm 61 is placed, which protrude into the head 62 over slide 118, the fabric support plate 60 has one goes. In the arm 61, the arm shaft 63 is mounted, the 60 slot 119, within which the lower ends of the seam guide shaft crank 65 acting on one end of the handwheel 64 and on the other end of the arm workpiece W are carried. The arm shaft crank 65 can be found 105, 106 before the start of their hem laying movements by the link 66 via the needle bar link 67.

with the up and down in the needle bar frame 68. Below the seam guide 105, 106 is a with

movable needle bars 69 connected, which on 65 several guide pins 120 provided guide plate

their lower ends carry the needles 70, which are arranged with 121. In Fig. 9 is for better overview

two arranged in the fabric support plate 60 and only see one of the guide pins 120 shown.

The grippers 71 shown schematically work together. give. The guide pins 120 are in bores

7 8

a bar 122 attached to the fabric support plate 60 with a negative slope. In this area will arranged displaceably. On the free ends of the seam guide 28 together with its supporting frame guide pin 120 is an adjusting ring 123 adjustable men 26 and the angle bracket 22 by means of the spring attached. One each between the guide plate 121 and 41 moves upwards and folds the Werkder Bar 122 arranged around the guide pin 120 5 piece edge hernete a further 90 ° around the folding rail 45 Spring 124 pushes in the starting position (Fig. 6). Finally, the rest of the end of the (Fig. 9) the guide plate 121 against the undersides of the workpiece edge by means of the support frame 26 with Hem guide 105, 106. the hem guide 28 influencing cam

At a distance in front of the stitch formation points below 35 between the upper layer of fabric and the underside of the support plate 109, the folding rail 45 is inserted on the fabric support plate 60 io. By the third a bracket 125 attached, which carries a motor 126 with and fourth folding, the second envelope is gebileinem circular knife 127, the latter protrudes through det. The L-shaped end of the guide plate 52 places a slot 128 on the bracket 125 against the first edge of the fold (FIG. 7).
the cover plate 130 fastened by the screws 129 and in the end position, the cam 42, which is arranged on the circumference of the camber, partially upwards out of the cover plate 130, hits the switch off. The cutting edge of the circular knife 127 is pin 48 of the switch 47 and turns off the motor 34 attached to the head 62 of the sewing machine.
Counterholder 131 for the workpiece covered. By turning the edge perpendicular to the

In the following, the operation of the in lateral workpiece edge can be a distortion of the

1 and 2 shown embodiment ao seams do not occur,

are explained: In the end position of the hem laying process (Fig. 7)

It is assumed that after about 270 ° rotation of the output shaft 33, the starting position shown in FIGS. 1 and 2 will now find the workpiece W with the double. A previously cut workpiece W is pelt-folded seam-shaped starting part by the seamstress in such a way placed on the support plate 46 of the workpiece edge under the stitch formation point that a certain length of the edge of the is pushed and sewn in a known manner. While the workpiece is being sewn next to the folding rail 45, the seam guide 28, together with the outer edge of the support plate 46, protrudes from the folding rail 45, supported by the guide plate and resting on the folding rail 45. For fixing 52, an infeed folding guide for the remaining edge of the workpiece W , fixing needles can be arranged 30 length.

be, which can be countersunk in the support plate 46- When the seam is finished sifting to the end of the workpiece. Then the support plate 46 is sewn, the motor is shifted in a known and not dar-workpiece W in the feed direction in such a way, set way by actuating a correspondingass the beginning of the workpiece edge under the switch reversed and switched on, whereupon the seam guide 28 to lie comes (Fig. 3). At the end 35 the seam guide actuates the control movements described in the displacement path, the support plate 46 executes the reverse order and moves it back to the switch pin 48 of the switch 47. This results in the starting position (FIGS. 1 and 2) being returned,
the gear motor 34 voltage, and the output The in the Fi g. The execution shaft 33 shown in 8 to 10 works as follows with the example of the curve attached to it:
disks 35, 36 set in slow rotation. 40 The seamstress first moves the support plate

The cam disks 35, 36 are designed in such a way, 109 with the fabric clamping frame 111 opposite, that initially the angle bracket 22 together with the support frame 26 and the seam guide 28 indicated by the arrow V (Fig. 9) through the feed direction of the sewing machine, namely as follows Cam disk 36, with the control surface 37 of which the distance until the feeler pin 38 clamped on the bolt 112 interacts, against the action 45 lever 113 on the stop of the spring 41 attached to the arm 61 is moved downwards, whereby the 114 hits The fabric clamping frame 111, at the beginning of the work lying above the folding rail 45, is pivoted around the bolt 112 and lifted from the support edge, as shown in FIG. The seamstress now lays the fold down. In the lower position of the base plate 109 determined by the downward position of the base plate 109, determined by the length of a control surface 37 of the 50 already hemmed fabric web S (FIG -Saumführer 28 takes over with the horizontal direction of arrow V, whereby the fabric clamping frame movable support frame 26 cooperating 111 due to its own weight in such a way on the cam 35 the control of the Saumführer 28 places fabric and it on the support plate 109 and moves it together with the Support frame 26 55 presses that the free ends of the folding rails 115, parallel to the lower surface of the folding rail 45 up to 116 approximately with the position shown in FIG. 5 directed towards the needles 70. The edge of the workpiece will complete the edge of the fabric. If you move it further, it will be folded by a further 90 °. During the last of the support plate 109, the clamped material under the described displacement movement is the guide the counter holder 131 for the circular knife 127, the sheet 52 from the side edge of the folding rail 45, to 60 sen motor 126 previously covered in the known manner by the first and second Folding was created, passed through. Circular knife 126 is then pressed off by means of the circumferential first envelope folded, then a workpiece from (FIG. 5). the length of fabric S cut off. The fabric edges of both

The control surface 37 of the cam 36 runs on the part of the line of intersection should then simultaneously

in the angular range in which the horizontal 65 are hemmed.

Displacement of the seam guide 28 takes place, incline In the displacement end position of the support plate

free. The starting parts of the

the cam disk 36 closes a region of fabric edges over which within the slits 119

Claims (3)

To lie south of the lower ends of the seam guides 105, 106 and under the folding rails 115, 116 (FIGS. 10 and 11). The support plate 109 actuates the switch 110 in the end position. This closes a circuit leading to the motor 73. The motor 73 starts up and sets the output shaft 74, on which the cam disk 79 effecting the height control of the carriers 90, 91 and the cam disk 76 effecting the lateral control of the carriers 90, 91 effecting, in slow rotation. The seam guides 105, 106 firmly connected to the carriers 90, 91 are subject to the influence of the two cam disks 76, 79, with their control surfaces 77, 81 the scanning cams 98, 99, 100, 101 formed on the carriers 90, 91 by means of the springs 102, 103, 104 are in a force-locking operative connection. During the rotary movement of the output shaft 74, the seam guides 105, 106 are first moved upwards by an amount determined by the control surfaces 81 of the cam 79 by means of the springs 103, 104, the initial parts of the previously cut fabric edges are, as shown in FIG folded, the spring-loaded guide plate 121 following the upward movement of the seam guides 105, 106 until the adjusting rings 123 rest on the underside of the bar 122. Subsequently, the carriers 90, 91 with the hem guides 105, 106 attached to them are pivoted about the bolts 94, 95 in opposite directions by an amount determined by the control surface 77 of the cam disc 76, with the fabric edges being turned over by a further 90 ° (F i g. 13) and are now above the associated folding rails 115, 116. The first and second folds form the first fold at each edge of the workpiece. The lateral surfaces of the guide plate 121 rest on the first fold-over edges and prevent these edges from escaping. The hem guides 105, 106 are then moved downwards by means of the cam disk 79 against the action of the springs 103, 104 and fold the ends of the fabric edges protruding beyond the folding rails 115, 116, as shown in FIG. 14, by 90 ° downwards. The remaining ends of the fabric edges are finally pushed in between the underside of the associated folding rails 115 and 116 and the fabric resting on the fabric support plate 60 by laterally directed movements of the seam guides 105, 106, as shown in FIG. The third and fourth folds form the second fold at each edge of the workpiece. Thus, the starting parts of the fabric edges on both sides of the cutting line are each formed into a double-folded hem. As soon as the molding process has ended, the cam 83 actuates the switching pin 85 of the switch 89. This interrupts the motor circuit and the motor 73 comes to a standstill. In this position, after about 180 ° rotation of the output shaft 74, the front ends of the formed hems are advanced to the stitch formation points and sewn in a known manner Hem lengths. In the case of elastic materials, the guide plate 121 prevents the edges of the first envelope from deflecting. When both hems have been sewn, the motor 73 is reversed and switched on by means of a switch (not shown), whereby the hem guides 105, 106 are returned to their starting positions in the reverse order while executing the control movements described. When this is reached, the cam 83 actuates the switching pin 84 of the switch 88 and thereby switches the motor 73 off. Patent claims: 1. Device on sewing machines for forming and guiding a double-folded hem with the help of a hem guide and a folding rail, characterized in that the hem guide (28 or 105, 106) for forming the hem has a rectangular movement around the folding rail (45 or respectively) corresponding to the outline of the hem cross-section 115,116) is granted. 2. Device according to claim 1, characterized by a guide plate (52 or 121) which can be moved with the aid of springs (53 or 124) into a position in which it is on the first edge of the fold around the folding rail (45 or 115, 116) placed seams. 3. Device according to claim 1 and 2, characterized in that the guide plate (52) on Hem guide (28) is hinged. Considered publications:
German Patent No. 706 148;
German Auslegeschrift No. 1137 296;
U.S. Patents Nos. 2,748,729, 2,053,257,
1621837. For this purpose 2 sheets of drawings 709 578/84 4.67 © Bundesdruckerei Berlin