EP0415171B1 - Process and device for wrapping the shank of a button stiched to a garment - Google Patents

Description

The invention relates to a method for wrapping the button stem of a button sewn onto a garment with a sewing thread, in which a wrapping thread made of an elastomeric plastic is wound under tension on the bundle of threads formed from the sewing thread between the button and the garment, and the thread end is then fastened becomes. The invention also includes an apparatus for performing the method.

When attaching buttons to items of clothing to form a handle between the button and the item of clothing, several requirements must be observed, which the mechanical processes used to date have either not completely met or could only be met by accepting further difficulties. For example, the button stem should be relatively stiff but still flexible so that the buttons do not hang on the one hand and the button can be moved into a suitable buttonhole on the other. In addition, the machine-sewn button should be secured against falling due to loosening of its wrapping and sewing threads. Finally, the wear caused by the button stem on the buttonhole should be kept as low as possible.

In a known method comprising two working steps, the button is first machined with a sewing thread sewn and fixed in the warp stitch process to form a bundle of threads between the button and the item of clothing, whereupon the bundle of threads is in turn wrapped with a thread using the warp stitch process using a special machine. Here, the thread bundle is not wrapped by wrapping the thread around the thread bundle, but rather by placing the thread on the side of the thread bundle while simultaneously knotting on the underside of the thread bundle using the chain stitch method using a gripping hook. This looping of the thread bundle according to the chain stitch method has various disadvantages. The knot formation on the underside of the bundle of threads creates a one-sided thickening of the loop, which leads to friction and wear in the buttonhole. Another disadvantage is the fact that the knots of the warp stitch wrap loosen when the clothes are worn and the bundle of threads no longer remains wrapped tightly so that the buttons can hang and eventually fall off.

From US-A-2 391 378 a complicated button wrapping machine is known, in which the button stem is wrapped twice by means of a needle guiding the wrapping thread. Both the beginning and end of the thread are anchored by means of the needle and other elements interacting with it in the immediate vicinity of the lower end of the button stem below the textile material to which the button with the stem is sewn on.

According to another known method for attaching buttons to items of clothing (DE 28 43 589 A1), the button stem of the machine-sewn button is wrapped with a thread under tension, the winding of which is swelled after the addition of a solvent and after it has evaporated off under contraction , so that the button stem is firmly enclosed with a homogeneous sleeve. Yarns made from cellulose acetate are used as the wrapping thread, which are wetted and glued with acetone. This known method leads to a stiff, durable and knot-free button handle, however the application of the solvent requires an additional work step, and the evaporation of the solvent poses a health hazard to the working personnel.

A method of the type specified at the outset has also already been described (DE 28 43 589 A1). The wrapping achieved with a wrapping thread made of elasto-fibers encloses the bundle of threads forming the button stem in such a way that the wrapping exerts constant pressure and brings the button to a standstill. However, it was correctly described that even with this procedure the elastic end of the yarn is difficult to link. If, however, the end of the elastic wrapping thread is not fastened sufficiently, the desirable, supple, flexible and flexible wrap dissolves immediately after cutting the wrapping thread with contraction in length of the elastic wrapping thread under tension.

The invention has for its object to achieve in a method of the type mentioned in a simple manner a reliable fastening of the wrapping thread end, which excludes re-dissolving the button shaft winding.

The object is achieved according to the invention in that the wrapping thread is drawn off after winding the bundle of threads from the button stem in a direction approximately perpendicular to its axis with an increased tensile force beyond its yield point before it is severed at the button stem.

The method according to the invention can be carried out extremely simply because only at the end of the winding process the tension in the winding thread is increased by the stated increase in tensile force. In this case, the end of the elastic wrapping thread is drawn in the vertical direction, ie approximately tangentially to the circumference of the button stem, after the wrapping completes the button stem in the vertical direction, making full use of the stretch to beyond its yield limit of the wrapping thread decreases the diameter of the wrapping thread inversely proportional to its increase in length. A wrapping thread with an initial diameter of approximately 0.2 mm decreases with a stretch of 500% to only approximately 0.04 mm. If the tensile force is increased further so that the yield point is exceeded, there is no further decrease in diameter. The increased tensile force acting on the winding thread is transferred even before the yield point is reached, or at least immediately afterwards, to the windings of the winding that were last wound, which also experience an increasing decrease in diameter as a result. The windings with a greatly reduced diameter of the wrapping thread can therefore penetrate between previously wound windings of the winding, between which they are firmly embedded, if the tensile force continues to act on them. If the wrapping thread drawn off with increased tensile force is severed close to the button stem, then the wrapping thread shows the tendency to resume its original shape, ie its initial diameter, in accordance with the memory of its elastomeric material. Since the last turns of the winding were firmly embedded under tension during their large diameter reduction between existing turns, the thread end can neither shorten nor regain the initial diameter. As a result, the thread end extending over several turns remains firmly clamped, to which the twist imparted to the winding thread during the winding process also contributes, which is also irreversible due to the fixed clamping. The turns of the winding formed from the winding thread can not move sideways because they are supported on the one hand by the textile material of the garment and on the other hand by the underside of the button, so that the clamping force can not be reduced by lateral evasion.

To cut through, the end of the wrapping thread, which is under increased tensile force, can be cut at the button stem, but preferably the wrapping thread is severed by tearing to the breaking limit, increasing the tensile force.

The use of a wrapping thread with an elongation of about 100 and 600%, preferably 400 to 600%, has proven to be advantageous for carrying out the method according to the invention.

Good results are achieved if a wrapping thread made of elastane fibers is used. Elastane fibers have proven themselves for decades in the production of elastic garments and consist of at least 85% by weight of segmented polyurethane. This material has exceptional abrasion resistance, a high yield strength, a high elongation at break, infusibility, resistance to oxidation and resistance to dry cleaning.

For the implementation of the method, the use of a stationary stick winding device is possible. In industrial garment manufacturing, it is common to complete the button sewing process in a single work station. This process consists of two different steps, namely first sewing on the button with a button sewing machine and then wrapping the button stem, i.e. of the bundle of threads forming the core of the button stem, with a stem winding machine.

Both machines are usually arranged side by side so that they can be operated by one worker. However, only one of the two machines can be operated while the other machine is at a standstill. To increase the economy, it would therefore be desirable if the process of button sewing by a worker can be carried out continuously and without interruption and the process of wrapping the button stems separately from the sewing on of the buttons is carried out, if necessary can even be combined with another work process, preferably with quality control.

It is therefore proposed in a continuation of the inventive concept an apparatus for performing the method, which makes achieving sewing of buttoned buttons overall more economical to achieve the specified reliable attachment of the wrapping thread ends to the button shaft winding than is possible using the above-mentioned stationary shaft winding machine. In this device, it is provided that a winding bell for the winding thread, a winding bell drive motor with a hollow shaft through which the winding thread is guided to the winding bell, and a magazine for receiving a winding thread supply are combined to form a hand-held device.

The handheld device designed in this way is no longer tied to the workplace of the button sewing machine, but can be used in any work area that follows the button sewing.

The handheld device is particularly compact and easy to handle if the magazine is designed as a handle. The winding bell, the drive motor and the magazine are advantageously arranged coaxially. However, the magazine can also be arranged at an angle, for example at right angles, to the common axis of the winding bell and the drive motor.

The manageability of the device proposed for carrying out the method can be further improved by the fact that the winding-bell drive motor with its Axis is arranged transversely to the axis of the winding bell and is non-positively connected to the winding bell via an angular gear.

The hand-held device, which has been improved in this way, has a very compact construction and facilitates the guidance of the device through ergonomically even more favorable handling when the drive motor is used as a handle. The housing of the drive motor is advantageously designed as a handle.

The angular gear is expediently formed by a pair of bevel gears, of which one bevel gear is attached to the hollow shaft fixedly connected to the winding bell, while the other bevel gear is attached to the motor shaft of the drive motor.

In a further embodiment of this device it is provided that the hollow shaft is rotatably mounted in a gear housing and is led out of it at both ends, the winding bell being fastened at one end, while the other end is adjacent to the magazine receiving the winding thread supply.

In this case, the housing of the drive motor is expediently connected to the transmission housing, as a result of which the compactness of the device is further improved.

The design of the magazine is advantageously carried out in such a way that the magazine is formed from a coil arranged at right angles to the common axis of the winding bell and hollow shaft and a coil carrier, to which the coil is rotatably and interchangeably attached and which is fixedly connected to the gear housing.

The device, which is designed as a hand-held device, is particularly suitable for use in the immediate successive wrapping of the button stems of a plurality of buttons, the button stems being wrapped in succession without cutting through the wrapping thread, whereupon the wrapping thread located between two button stems is pulled from both button stems and severed on both button stems. In this case, the severing, which is preferably achieved by tearing off, can take place immediately after a plurality of buttons have been sewn on, but also at any later point in time, without thereby endangering secure fastening of the thread ends.

Fig. 1

zeigt einen Längsschnitt einer stationären Vorrichtung während des Umwicklungsvorganges,

Fig. 2

zeigt die Vorderansicht des zur Halterung des Knopfes und des Knopfstiels während des Umwicklungsvorgangs verwendeten Metallschilds der Vorrichtung nach Fig. 1,

Fig. 3

einen Längsschnitt durch eine erste Ausführungsform der als Handgerät ausgebildeten Vorrichtung und

Fig. 4

einen partiellen Längsschnitt durch eine zweite Ausführungsform der als Handgerät ausgebildeten Vorrichtung.

For a more detailed explanation of the method according to the invention, the device according to the invention and the preferred use of the device, reference is now made to the drawings, in which the device for wrapping around the button stick is shown in several embodiments in a schematic representation. In the drawings, corresponding parts are identified by the same reference numerals.

Fig. 1

shows a longitudinal section of a stationary device during the wrapping process,

Fig. 2

1 shows the front view of the metal plate of the device according to FIG. 1 used to hold the button and the button stem during the wrapping process,

Fig. 3

a longitudinal section through a first embodiment of the device designed as a handheld device and

Fig. 4

a partial longitudinal section through a second embodiment of the device designed as a hand-held device.

The stationary device shown in FIG. 1 has a winding bell 3 which can be rotated about the dash-dot line in the device and which is provided with a concentrically mounted hollow shaft through which the winding thread 1, which is required for wrapping the button stem, is guided. A thread tensioner 2 is used for fine adjustment of the thread tension. After exiting the hollow shaft, the winding thread is passed through an eyelet 4 on the edge of the winding bell 3 and inserted loosely into the slot of the shield 5.

The shield 5 is a thin-walled, arched and provided with the vertically arranged slot metal shield and serves as a carrier for the already sewn button 6 and the thread bundle 7, which is initially formed from the sewing thread. Before the wrapping process is started, the sewn button 6 with the Thread bundle 7 inserted into the slot of the shield 5 so that the button and thread bundle 7 protrude into the cavity of the winding bell 3. The area of the garment 10 which carries the button 6 is located on the back of the label.

The curved shield 5 is fastened on a device 8, which is only indicated in FIGS. 1 and 2 and which can be moved forwards and backwards and inclined in the direction of the winding bell 3. This movement allows the button 6 with the bundle of threads 7 to be moved deeper or less deeply into the cavity of the winding bell 3.

After the described insertion of the button 6 and the bundle of threads 7 in the slot of the shield 5, the winding bell 3 set in rotation, a winding extending over the entire length of the thread bundle 7 is formed by axial relative movement between the winding bell 3 and the device 5 carrying the shield 5 from the winding thread until the button stem consisting of thread bundle and winding is completed. The thread bundle is wrapped around in a short time and the button is lifted up out of the plate 5. The wrapping thread, which has not yet been cut, is now grasped directly on the button stem and pulled away so far approximately perpendicular to the axis of the button stem and tangentially to its circumference by corresponding tensile force that no further stretching occurs. The winding thread is then torn off directly on the button stem by further increasing the tensile force. The whole process is very simple and fluent: lifting off the shield, pulling the thread away and tearing off the thread on the stem. The button stem obtained is characterized by suppleness, flexibility and durability. A redissolution of the winding formed from the winding thread is excluded because of the clamping of the last turns of the winding thread forming the thread end between previously laid turns of the thread, as described above.

To explain the first embodiment of the device designed as a handheld device, reference is now made to FIG. 3. An electric motor 11, preferably a low-voltage direct current motor, drives the winding bell 3 with the aid of a hollow shaft 12. The elastic winding thread 1 is drawn off from a spool 14 located in a magazine 13 and guided through the hollow shaft 12 to the winding bell 3, where it emerges during the winding process at the edge of the bell 3 and winds around the bundle of threads 7 of the button stem.

The winding process with this first hand device is carried out as follows: the yarn end, ie the free end of the Wrapping thread 1 is fixed by lightly pressing the garment 10 with a finger and the wrapping bell 3 is brought into slight contact with the surface of the garment 10, the sewn button 6 should be located in the center of the bell if possible. The electric motor 11 is then put into operation for a certain period of time via a separate control (not shown), as a result of which the winding process is carried out. The winding bell 3 is then lifted off the button 6 and preferably placed on the next button without tearing the thread 1. This process can be continued as desired, so that practically any number of items of clothing can be processed one after the other. So it is possible to carry out the wrapping of the button stems on items of clothing which are suspended on the treadmill without the yarn or the thread 1 having to be torn off. The thread sections located between the buttons are torn off at any later point in time. Here (with the exception of the first wound stem), both ends of the thread, ie the beginning and end, are attached to each button stem in accordance with the procedure. Of course, the device according to the invention can also be used with correspondingly good results for wrapping around the button stems of individual buttons.

The second embodiment of the device designed as a hand-held device is described below with reference to FIG. 4. A hollow shaft 12 'is rotatably and axially immovable in a gear housing 19. The hollow shaft 12 'is led out of the gear housing 19 with both ends, a winding bell 3 being attached to one end, while the other end is adjacent to a magazine 13' for receiving a supply of winding thread. The magazine 13 'consists of a bobbin 21 fixed to the gear housing 19 and a supply bobbin 14 for the winding thread 1, which is arranged at right angles to the axis of the hollow shaft 12' and is rotatably and interchangeably attached to the bobbin 21. The winding thread 1 running from the bobbin 14 is guided through the hollow shaft 12 ', then through a slot 22 in the wall of the winding bell 3 and finally through an eyelet 4 provided on the circumference of the winding bell 3.

The hollow shaft 12 'passes through a cavity 23 located in the interior of the gear housing 19, in which there is an angular gear 15 formed from two bevel gears 16 and 17. The bevel gear 16 is concentrically attached to the hollow shaft 12 ', while the bevel gear 17 is attached to the motor shaft 18 of a drive motor 11', which is preferably designed as a DC motor. The drive motor 11 'is surrounded by a motor housing 20 which is connected to the gear housing 19. In this arrangement, the axis of the hollow shaft 12 'and the axis of the drive motor 11' form a right angle. The motor housing 20 of the drive motor 11 ', which is shown only broken off in the drawing, is designed as a handle which, because of its location on the overall device, permits convenient and precise handling and guidance of the device. The drive motor 11 'can be designed as a cordless battery motor.

The winding process which can be carried out with the hand-held device according to FIG. 4 corresponds to that which was described with reference to FIG. 3.

Claims (14)

1. A process for winding round the stem of a button sewn by a sewing thread to an article of clothing, in which a winding thread made from an elastomeric plastics material is wound under tension onto the thread bundle formed from the sewing thread between the button and the article of clothing and the thread end is subsequently fixed, characterized in that, after winding round the thread bundle, the winding thread is drawn off the button stem in a direction substantially at right angles to the axis with a tension increased to beyond its yield point before it is separated at the button stem.
2. A process according to claim 1, characterized in that the winding thread is separated by tearing off, accompanied by an increase in the tension to the breaking limit.
3. A process according to claim 1 or 2, characterized in that use is made of a winding thread with an elongation of approximately 100 to 600 %, preferably 400 to 600 %.
4. A process according to any one of claims 1 to 3, characterized in that a winding thread is used formed from Elasthan-fibres.
5. A process according to any one of claims 1 to 4, characterized in that the button stems of several buttons are successively wound without any separation of the winding thread, and that subsequently the winding thread located between in each case two button stems is drawn off the two button stems and is separated at said two button stems.
6. A device for performing the process according to claims 1 to 5, characterized in that a winding bell (3) for the winding thread (1), a winding bell drive motor (11, 11') with hollow shaft (12, 12'), through which is passed the winding thread (1) to the winding bell (3), and a magazine (13, 13') for receiving a winding thread supply being combined to form a hand-operated device.
7. A device according to claim 6, characterized in that the magazine (13) is constructed as a handle.
8. A device according to claims 6 or 7, characterized in that the winding bell (3), the drive motor (11) and the magazine (13) are arranged equiaxially.
9. A device according to claim 6, characterized in that the winding bell drive motor (11') has its axis transverse to the axis of the winding bell (3) and is in force-locking driving connection with the said winding bell (3) by means of a miter-gear.
10. A device according to claim 6, characterized in that a casing (20) surrounding the drive motor (11') is constructed as a handle.
11. A device according to claim 9 or 10, characterized in that the miter-gear (15) is formed by a pair of bevel wheels, wherof one bevel wheel (16) is fitted in non-rotary manner to the hollow shaft (12') fixed to the winding bell (3), whilst the other bevel wheel (17) is fixed to the shaft (18) of the drive motor (11').
12. A device according to any one of claims 9 to 11, characterized in that the hollow shaft (12') is mounted in rotary manner in a gear casing (19) and the two ends thereof are led out of the casing, the winding bell (3) being fixed to one end, whilst the other end is positioned adjacent to the magazine (13') receiving the winding thread supply.
13. A device according to any one of claims 9 to 12, characterized in that the casing (20) of the drive motor (11') is connected to the gear casing (19).
14. A device according to any one of claims 9 to 13, characterized in that the magazine (13') is formed from a bobbin (14') positioned at right angles to the common axis of the winding bell (3) and the hollow shaft (12'), as well as a bobbin carrier (21), to which the bobbin is fixed in a rotary and replaceable manner and which is firmly connected to the gear casing (19).

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