CZ20023559A3 - Device for feeding material to be sewn - Google Patents

Abstract

The invention relates to a device for conveying articles to be sewed, which is provided for a sewing device or sewing machine. Said device comprises at least one material advancing device for advancing the article to be sewed in the advancing direction of the material with an advancing speed defined by the speed of the machine and by the stitch length. The device also comprises at least one material conveying supplementary device which, in the form of a pressing means, subjects the upper material layer of the article to be sewed to a pressing force. The material conveying supplementary device rotates with a rotational speed, is arranged behind the material advancing device in the advancing direction of the material and can be proportionally driven with regard to the speed of the machine and to the stitch length. At least one device can increase the pressing force, which is exerted by the device onto the upper material layer of the article to be conveyed, with an increasing speed of the machine and/or in addition to the proportional increase with increasing speed of the machine, can further increase the rotational speed of the material conveying supplementary device.

Description

Device for feeding sewn material

Technical field

BACKGROUND OF THE INVENTION The invention relates to an apparatus for feeding sewn material intended for a sewing machine 5 or a sewing machine provided

- at least one device for advancing the sewn material in the material feed direction at a feed rate determined by the number of machine revolutions and the stitch length, and

- at least one additional material feeding device in the form of a pressing tool acting on the upper material layer and rotating at a rotational speed, which is arranged in the material feed direction downstream of the material feeding device and is movable proportionally to the machine speed and stitch length.

BACKGROUND OF THE INVENTION

In this connection, an additional material feeding device (cf. the corresponding prior art in US-A-4 182 251) compensates for the feed between the upper and lower layers by the sewing device of the material to be processed (in the following the term "sewing machine" also includes sewing machines). applies to both sewing machines and sewing machines). In practice, this displacement occurs when the lower material layer is forcefully carried by the teeth of the material feed device, while the upper material layer is carried only by friction between the upper material layer and the lower material layer.

For this friction to be effective now, the suture material is held by the so-called material pressure device during stitching and feeding of the seamed material so that the upper material layer and the lower material layer are compressed between the material pressure device and the material feed device and fed by the material feed device. direction of material feed.

During this feed phase, frictional forces are now generated between the topsheet of the sewn material being fed and the material thrust device, which can cause a feed in the feed length between the topsheet and the backsheet. This is strictly unwanted, because sewing results negatively affecting the sliding effect already occur at low speeds of the main shaft of the sewing machine and thus at low feed speeds; the sliding effect is the stronger the higher the speed and the feed speed.

The basis for this is seen in the method of operation of the material feed device, which moves upward at the beginning of the feed phase, i.e. in the direction of the material feed device, so that the teeth of the material feed device can engage the lower layer of the sewn material. At this time, the material to be sewn moves the material presser - to some extent forced - upwards so that the inertia mass pressure of the material presser increases on the material layers.

The material feed device performs approximately an ellipse-shaped movement: while the material pressure device moves a little upwards, the material feed device begins to move the material layers in the feed direction. During this feeding phase, the pressure of the material pressing device is now greatly reduced until the spring force is applied upwards, that is to say from the material feed device, the movement of the material pressing device and the material pressing device again presses on the sewn material.

In the extreme case, it may even happen that the material pressing device loses contact with the sewn material for a short period of time by its vertical upward movement and thus breaks the frictional connection between the upper material layer and the lower material layer. the more the higher the speed of the main shaft of the sewing device and of this feed rate, so that with the sewing rate, which is a measure of the feed rate, the feed between the upper material layer and the lower material layer increases steadily.

At the end of the feed phase, the material feed device moves downward, that is, away from the material pressing device, so that the pressure of the pressing device decreases again briefly. However, the last phase has no significant effect on the displacement between the topsheet and the backsheet.

In order to compensate for the sliding effect, an additional material feeding device intervenes on the upper material layer. When feeding the material exclusively, the additional material feeding device causes a so-called negative displacement, i.e., the upper layer of the material is overtaken by the lower layer of the material.

If the rotation speed of the auxiliary material feeding equipment is correctly adjusted to the machine speed and to the set stitch length, the stitch path should be non-displaceable.

Thus, a device for feeding material for a sewing machine is known (cf. DE 29 36 697)

C2) in which the driven feed roller is connected with a thrust mechanism which serves both to adjust the gap between the material support surface and the material feed roller (roller) so that the material feed roller cannot directly contact the material support surface and adjusting the preload force by which the material feed roller pushes the work against the material support surface; however, this set preload force remains unchanged during the end of the sewing.

Further, a sewage feed device (cf. DE 29 27 869 C2) is known in which an additional material feed device is intended to perform a somewhat larger feed value (feed value) than the material feed device when forward feeding;

in order to keep the sewn material under tension in the feed direction in the feed direction. This, when sewing the topsheet and the backsheet, will prevent "slipping", in other words, preventing slippage; however, the set ratio between the feed value of the material feed device and the feed roller of the additional material feed device remains constant during the sewing process to the number of machine revolutions.

However, it has been shown that the displacement between the topsheet and the backsheet is dependent on the speed of the sewing machine main shaft, i.e. the so-called machine speed, so with this conventional machine at varying ratios such as fluctuating sewing machine speed and thus at variable feed rates, no satisfactory and perfectly matched sewing results are achievable.

Based on the above-mentioned disadvantages and drawbacks, the present invention aims to provide a machine for feeding sewn material of the same kind such that, even at varying ratios (such as at varying speeds of the sewing machine main shaft and hence at variable feed speed)

• '· · • · · · • ♦ » • · · ♦ • · · · * ·· • · · • «'♦ • · • · · · · • · · · · ·

convincing, in particular perfectly matched sewing results, are always achievable by the material layer and the material base layer.

SUMMARY OF THE INVENTION

This object is solved by an apparatus for feeding sewn material according to the overriding concept of the main claim, in which according to the teaching of the invention it is by means of at least one device

- which is the contact force exerted by the additional material feeding device on the top layer of the sewn material being fed, increasing with increasing machine speed, and / or

- the rotation speed of the additional material feeding device is increased in addition to the proportional increase with increasing machine speed.

This surprisingly takes into account the fact that the machine speed and / or the stitch length and thus the feed rate influence the way of operation and the function of the additional material feeding device. To this end, the pressing force exerted by the additional material feeding device on the top layer of the sewn material to be fed is increased by at least one device with increasing machine speed. As a result, the fact that the displacement between the upper material layer and the lower material layer increases with increasing machine speed can be accommodated, so that also an additional material feeding device must exert an increasing tensile force in the upper material layer.

Alternatively, or in addition to this, according to the teachings of the invention, the rotational speed of the additional material feeding device is further increased in addition to the proportional increase with increasing machine speed. It can also be accommodated by the fact that the displacement between the upper material layer and the lower material layer increases with increasing machine speed, so that also the additional material feeding device has to exert an increasing tensile force in the upper material layer.

In order to be able to select the thrust force of the auxiliary material feeding device and / or the rotational speed of the auxiliary material feeding device in dependence on the machine speed, at least one device is provided, which may for example be designed as at least one regulating member.

According to preferred embodiments which can be implemented with each other independently or in conjunction with one another, it is determined that:

the pressing force and / or the rotation speed, preferably by means of the device, is additionally adaptable to the properties of the sewn material being fed; and / or I

- the contact force F _{p is} given by the equation

F _p = F ₀ + R 11, being

F _o constant force,

R is the coefficient of friction, the magnitude of which is determined by the friction ratios between the additional material feeder and the topsheet and n is the number of revolutions of the machine; or

the number of revolutions of the device is a measure of the speed of rotation of the additional material feeding device 15 or is directly the speed of rotation of the additional material feeding device; or

- the number of revolutions n _{p of the} device is given by the equation n _p = kn L,

while it is to adjustment factor, n machine speed and or L stitch length;

- auxiliary material transport operates at low speed (n _p <500 25 min ¹⁾ of the device in the intermittent mode; or

- the opening and closing times of the machine are determined by the angular position of the main shaft of the sewing machine or the sewing machine; or

the additional material feeder operates in the high speed range (n _p > 500

- min '( ¹ ) continuous installation; and / or • 4 4 ·· ·· • 9 »'In%' 9 9

the feed path of the additional material feed device pertaining to the forming process is larger, particularly slightly larger than the feed path of the material feed device; or

- the contact force of the additional material feeding device and / or the speed of rotation of the device 5 is electronically controllable; or

at least one electronic control device is provided for controlling the pressing force of the additional material feeding device and / or the speed of the device; or or

- the number of revolutions of the machine is determinable in the electronic control device; or

- the electronic control device receives the stitch length information by entering via at least one control panel; or

- the electronic control device receives information on the properties of the sewn material to be fed by entering by means of at least one control panel; or

the device is preferably provided with at least one DC current driven by a linear motor; or

the linear motor is provided with at least one stator element configured as a housing; or

at least one rotor element formed as a drive rod is mounted in the stator element; or

the stator element is arranged on the back of the head of the housing of the sewing device 20 or the sewing machine; or

- the device has - at least one preferably direct current driven drive motor,

at least one transmission arranged between the drive motor and the additional material feeding device, and

at least one transmission element arranged between the gearbox and the additional material feeding device to transmit the movement to the additional material feeding device; and / or 30 - the scaling factor k is given by the equation

-J'.j 'i k

• · ·

while it is ki parameter for the diameter of the auxiliary feeding device material, for linear motor constant and for conversion gearboxes, k ₂ measure for functional dependence of conversion between upper layer material and the bottom layer of material at the speed machines and k ₃ a parameter for the properties of the sewn material being fed; or

- a device provided with at least one stator element in connection with a supporting element on which the drive motor, gearbox and transmission element are fixed; or

- a load-bearing support element secured against rotation; or

a support element rotatably secured by means of at least one guide rod;

or

- a support member prestressed by means of at least one resilient low-mass coupling member; or

- the coupling element is at least one coil spring; or

- the additional material feeding device is designed as at least one rotating roller, in particular as at least one rotating take-off roller; or

the device is configured as at least one regulating member.

In particular, the following can be explained for the preferred embodiments, which can be provided independently or interconnected:

According to a further inventive embodiment of the present apparatus, the pressing force and / or rotation speed, preferably by means of the apparatus, can additionally be adapted to the properties of the sewn material being fed. Thus, the fact that the displacement between the topsheet and the backsheet is determined not only by the number of machine revolutions but also by the properties of the sewn material being fed, in particular the friction ratios between the backsheet and the topsheet,

as well as, in particular, frictional ratios between the topsheet and the material pressing device.

SUMMARY OF THE INVENTION [0009] The invention is based on the fact that, when sewing the topsheet and the backsheet, the uneven pressing forces of the material and the resulting uneven feed ratios resulting from displacement, i.e. delay of the topsheet, can be compensated by retrofitting , an individually adapted additional material feeding device acting on the topsheet.

In this way, the tensile stress is slightly exerted on the upper material layer, the pressure value of the auxiliary material feeding device being importantly influenced according to the invention, while the slight pressure force can advantageously influence the timely slippage of the additional material feeding device. material; correspondingly, a higher thrust force may cause later slipping of the additional material feeding device and thus greater tensile stress in the upper material layer.

In this case, the tensile stress during the short-term phases of the low material contact force causes the upper material layer to stretch slightly relative to the lower material layer, thereby compensating for the otherwise occurring displacement.

With respect to the mode of operation and the function of the present machine for feeding the sewn material, it is appreciated that the displacement between the topsheet and the backsheet material occurs substantially at the beginning of each feed phase, since at this time the material pressure device pressure the material feed device drops strongly. For this reason, the additional material feeder is of particular importance since, according to the teachings of the present invention, the adjustable force by which the additional material feeder presses on the material layers affects the elongation in the material layers:

Thus, at the beginning of the feed phase, in which the material feed between the upper and lower material layers is caused by the weakening pressure of the material pressing device, this stretching of the upper layer relative to the lower layer in the material feed direction layer of material pulls. Thus, if the parameters are correctly adjusted, a longer seam can be achieved without sliding between the topsheet and the backsheet.

Conveniently, the corresponding value of the force _{p p can be} imitated by the equation

F _p = Fo + R n, where F _o is a constant force, R is a coefficient of friction, the magnitude of which is determined by the friction ratios between the additional material feeder and the topsheet, and n is the machine speed.

Thus, it is apparent from the equation F _p = F _o + R n that, in addition to the constant friction coefficient and the machine speed independent of the ratio, the contact force is substantially suitably linear with the coefficient of friction between the additional material feeding device and the topsheet , or is substantially linear with the machine speed.

Depending on the relevant technical facts, the number of revolutions of the device may be a measure of the speed of rotation of the additional material feeder, or - for example, in the case of direct transmission or in direct gear to slow - directly.

In this case, the number of revolutions np _{of the} device can preferably be given by the equation n _p = kn

L, where k is the fit factor, n is the machine speed and L is the stitch length.

Thus, it is apparent from the equation n _p = kn L that the rotational speed of the device and thus the rotational speed of the additional material feeding device - in addition to the subsequently specified adjustment factor - is expediently substantially linear with the rotational speed of the machine, or is substantially linear with length stitch magnifiable.

The fit factor k is expediently given by the equation k = ki k ₂ k ₃ , where k, is a parameter for the diameter of the additional material feeder, for the linear motor constant (compare below) and for the transmission ratio (compare below) , k ₂ is a measure of the functional dependence of the feed between the upper material layer and the lower material layer on the machine speed and k ₃ is a parameter for the properties of the sewn material being fed.

·· ···· • »· ·· · » • · · • · · · Á · · • ··· • * · • · · • · • é · • · · ··· ·· ·· ·· «·

It is therefore clear from the equation k = kj k ₂ to ₃ that the number of revolutions of the device and thus the speed and rotation of the additional material feeding device is dependent on the technical | characteristics and assumptions of the equipment and attachment of the material feed (- S> factor k]), the function of displacement between the upper material layer and the lower material layer -1 through the machine speed (~> factor k ₂ ), and the characteristics | of sewn material (-> J factor k ₃ ).

According to a preferred embodiment of the invention operates in the auxiliary material transport means at low speed (n _p <500 min ^_1) device in the intermittent mode. This means in other words that the drive motor of the device is switched on in the feed phase I and in the non feed phase. The switching-on and switching-off times of the device 1 are preferably determined by the angular position of the main shaft of the sewing machine or of the sewing machine. AND

According to a preferred embodiment of the invention, the rotational speed n _{p is of the} order of about 1

500 ^min-1 switches to a continuous drive, i.e., an additional device for feeding material may also in the high speed (n _p> 500 MINX ¹⁾ of the device to work in a continuous fashion. In this context, however, it is considered that in the rpm n I _p of about 500 min ^-1 due to the mass inertia and the elastic behavior of the elements of the drive intermittent motion besides, gradually turning into a seemingly continuous.

In this context, it is important that the passage of the layers of material is dependent on the frictional I ratios of the additional material feeder and the topsheet (and its properties). Also with respect to this, the elongation in the suture material is influenced by the adjustable force that the additional material feeding device pushes against the suture material. AND

In a further suitable embodiment of the invention, the feed path of the additional material feeding device I per stitch forming process is greater, particularly slightly greater than the I feed of the material feeding device. This technical measure also ensures that the stitched material is still held under tension in the feed direction in the feed direction, so that when the upper material layer and the lower material layer are sewn, I prevents the formation of displacement. I ···· • · ·· · * ► »ft» · ♦ · · · · ·

The foregoing embodiments, features and advantages of the add-on material feed device are particularly pronounced when the add-on material feed device according to another suitable embodiment of the invention is formed as at least one rotating roller, in particular as at least one rotating take-off roller.

According to a particularly inventive embodiment of the present sewing material feed device, the contact force of the additional material feed device and / or the rotational speed of the device (-> rotation speed of the additional material feed device) is electronically controllable. For this purpose, at least one electronic control device can be provided to cross the contact force of the additional material feeding device and / or the rotational speed of the device (-> rotation speed of the additional material feeding device)

Since the pressing force of the auxiliary material feeding device and / or the rotational speed of the auxiliary material feeding device can now depend inter alia on the rotational speed of the machine, the rotational speed of the machine according to a suitable embodiment of the invention can be determined in an electronic control device. so that the pressing force of the additional material feeding device and / or the rotational speed of the device (-> rotational speed of the additional material feeding device) can be adjusted at any time to the speed of the machine.

In addition, the rotation speed of the additional material feeding device can be determined not only by the machine speed, but also by the stitch length. Since the stitch length of the sewing device is generally adjusted mechanically, the stitch length is generally not known to the electronic control device. Finally, not only for this reason can the electronic control device receive the stitch length information expediently by inserting it through at least one control panel. The nominal value for the rotational speed of the drive motor of the device and hence its speed can then be determined by at least one computer algorithm of the invention.

In addition, the contact force of the additional material feeding device can be determined not only by the machine speed, but also, inter alia, between the additional material feeding device and the topsheet of the sewn material acting by the frictional force. Since this frictional force in a sewing device is generally dependent on the properties of the material being fed, the friction force is generally not known to the electronic control device. Finally, not only for this reason, the electronic control device can receive information about the properties of the sewn material to be fed expediently by inserting it through at least one control panel. The nominal value for the thrust force of the additional material feeding device can then be determined by at least one computer algorithm of the invention.

Thus, when the device is advantageously provided in particular with one preferably direct current driven by a linear motor, which is in practice provided with at least one stator element as a housing, in which at least one rotor element formed as a drive rod is expediently disposed and / or preferably, by at least one particularly direct current driven drive motor, the thrust force of the auxiliary material feed device and / or the rotational speed of the device (→ rotational speed of the auxiliary material feed device) can be controlled by at least one (current) controller.

In doing so, the invention takes advantage of the fact that the linear thrust applied to the linear motor and / or the rotational speed or rotation speed transmitted by the drive motor is directly proportional - in any case largely to the linear motor or the drive motor supplied to the current. For this reason, the current of the linear motor or the drive motor current is electronically controlled and thus affects the required pressure of the additional material feeding device and / or the desired rotational speed of the device (-> the desired rotational speed).

It may be of great importance to the invention that the force of the linear motor need not be measured. Suitably, the additional material feeding device should be designed so that it can be lifted from the top of the suture material, for example, the suture material can be removed from the sewing device. This can also be done using a linear motor, note that the linear motor need not perform any positioning function in this context. With regard to the design, features and advantages of the linear motor, the type of motor is fully taken into account, as described in the German patent application DE 199 45 443.4 or in the international patent application WO 00/18997.

to * • • to · it" • it • it it »» toto · • it • • tor · • » • · ' • it • to · • • • • ··· • • to> Ví · to » it· ····

In this context, according to a particularly inventive embodiment of the present sewing material feeding apparatus, both the initial value and the feed rate 1 dependent part of the thrust force can be appropriately parameterized and, for example, f adjusted to the respective sewing I 'and ratios by at least one control panel. *

According to a particularly inventive embodiment of the invention, the device b '

- at least one stator element made as a housing (cf. above), which can be connected (rigidly) to at least one mounting plate and / or which can be arranged on the back of the sewing head housing,

- at least one rotor element formed as a drive rod (compare above),

- at least one preferably direct current driven drive motor (cf. above),

at least one transmission arranged between the drive motor and the additional material feeding device, and

- at least one transmission element arranged between the gearbox and the additional material feeding device for transmitting movement to the additional material feeding device.

At the same time, the device can have at least one support element, preferably secured against rotation, in connection with the rotor element 1, on which the drive motor, gearbox and transmission element are secured (anti-rotation support of the support element can be effected for example by means of a guide rod).

and

In addition, an embodiment in which the support element is biased by means of at least one springing low-mass coupling element, preferably by means of at least one coil spring, is also recommended. With regard to the embodiment, the features and advantages of the coupling element are fully taken into account in the German patent application DE 199 45 443.4 or in the international patent application WO 00/18997, in particular with regard to the coupling element associated with the current-saving working method.

Further embodiments, features and advantages of the invention will be further described in the drawings according to Figs.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 shows an exemplary embodiment of the sewing material supplying device according to the invention in sectional side view. Fig. 2 shows a diagram of the force F of the material pressing device 5 on the angle of rotation of the sewing machine main shaft. FIG. 4 shows a schematic representation of the interaction between the control mechanism and the electronic control device of the sewing machine; and FIG. 5 a diagram of the contact force F _{p of the} additional material feeding device versus the speed n of the machine.

Identical positions refer to elements or features of the same or similar design in Figures 1 to 5.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows a sewing machine 10 (see FIG. 4) for a sewing machine 10 or a sewing machine 10 (see FIG. 4), which has an embedded machine in the stitch plate 7 and a material feed to feed the sewn material in the material feed direction D (FIG. .l arrow). In addition, the sewing apparatus 10 (hereinafter referred to as "sewing apparatus" also includes sewing machines, the invention relates both to the sewing machine and to the sewing machines) on the topsheet 8 of the sewn material with a pressing force ^K 20 F _p acting and rotating speed _E U rotating attachment 2 for feeding the material, which is arranged in the material feed direction D as well as material feed apparatus.

The additional material feeding device 2 serves at the same time to compensate for the feed between the upper material layer 8 and the lower material layer 9 by the sewing device.

10 of the sewn material to be processed. This displacement occurs when the lower material layer 9 is forcefully entrained by the teeth of the material feed device 1, while the upper material layer 8 is carried only by friction between the upper material layer 8 and the lower material layer 9.

In order for the friction to be effectively applied now, the suture material is held by the material presser 6 during stitching and feeding of the seamed material, so that the upper material layer 8 and the lower material layer 9 are between the material pressure device 6 and the material.

The material feed device 1 is compressed and fed by the material feed device 1 in the feed direction.

During this feed phase (see FIG. 2), frictional forces are now generated between the topsheet 8 of the sewn material being fed and the material pressure device 6, which can cause a feed in the feed length between the topsheet 8 and the backsheet 9. This sliding effect occurs already at a low speed n of the sewing machine main shaft machine 10 (see FIG. 4) and hence at low feed speeds; the sliding effect is all the more powerful as the machine speed and feed speed increase.

The cause of this can be seen in the way the material feed device also that 10 to start feeding stage (see Figure 2: angular position on _a) moves upward, i.e., in the direction of the thrust device 6 of material in order to feed teeth of LK material to engage the bottom layer 9 of the sewn material. During this phase, the material to be sewn moves the material presser 6 - to some extent forced - upwards (see FIG. 1: arrow A), so that the pressure of the material layers 8, 9 increases by the inertia of the material presser 6.

The material feed device 1 performs an approximately elliptical movement: while the material pressing device 6 is still moving slightly upwards, the material feed device 1 begins to move the material layers 8, 9 in the material feed direction D. During this feeding phase, the force F of the material pressing device 6 now weakens strongly (see Fig. 2: a strong drop by the material pressing device 6 of the developed force F depending on the angle of rotation about the main shaft of the sewing device 10). the material pressing device 6 and the material pressing device 6 again push the sewn material.

In the extreme case, it may even happen that the material pressing device 6 loses contact with the sewn material for a short time by its vertical upward movement and thus the friction connection between the material upper layer 8 and the material lower layer 9 is broken. This phenomenon is more pronounced the higher the speed of the main shaft of the sewing device 10 and thus the feed rate, so that with the sewing rate, which is a measure of the feed rate, the feed between the upper material layer 8 and the lower material layer 9 increases.

*

At the end of the feed phase (see Figure 2: angular position 0 _e) moving the device I to downward displacement of the material, i.e. in the direction away from the thrust device 6 of the material so that the pressure of the pressure means 6 decreases again briefly material. However, the last phase has no significant effect on the displacement between the upper 8 material layer and the lower 9 material layer.

Now, in order to compensate for the sliding effect, an additional material feeding device 2 occupies the material upper layer 8 (see FIG. 1). In this case, the so-called &quot; negative displacement &quot;

If the rotation speed U _E (see Fig. 1) of the attachment 2 for feeding the material to the machine speed n (see Figs. 4 and 5) and the set stitch length L is set correctly, the stitch path can be produced without feed. In this case, the suture feeder according to the embodiment of FIGS. 1 to 5 is arranged such that even under varying conditions (such as at a variable speed n of the main shaft of the sewing machine 10 and hence at a variable feed rate) convincing, in particular completely identical, sewing results are achievable by the upper material layer 8 and the lower material layer 9.

To do so, _the pressure force Fp exerted by the shape of a rotating cylinder made auxiliary exhaust means 2 on the upper material layer 8 of the sewn material and / or the peripheral speed Up of _the through device 3 (see Figure 3), adjustable feed rate. Thus, in the example shown in FIGS. 1-5 by the device 3 _the pressure force Fp exerted by the auxiliary device 2 for feeding material into the upper layer 8 of the sewn material, with the passing machine rpm n extensible and / or the rotational speed U _E in addition to the proportional increase, as the number of revolutions n increases, it can be further increased.

This takes into account the fact that the number of revolutions per / or the length of the stitch L and by means of which the feed rate influences the way of operation and the function of the additional material feeding device 2. For this purpose, the pressing force F _E exerted by the additional material feeding device 2 on the top layer 8 of the sewn material to be fed by means of the device 3 with increasing machine speed n is increased (see FIG. 5).

Λ

As a result, it can be taken into account that the displacement between the material upper layer 8 and the material lower layer 9 increases with increasing speed n so that the additional material feeding device 2 also has to develop an increasing tensile stress in the material upper layer.

Alternatively or additionally to the rotational speed of _the auxiliary device 2 for feeding the material in addition to the proportional increase with increasing number of revolutions n further zvýšitelná. It can also be taken into account that the displacement between the upper material layer 8 and the lower material layer 9 increases with increasing speed n, so that also the additional material feeding device 2 must develop an increasing tensile stress in the upper material layer.

To thus allowing the downward force F _S of the attachment 2 for feeding material and / or the rotational speed of _the auxiliary device 2 for feeding of the material depending on the number of revolutions n vote is a device 3 which in the example shown in Figure 3 operates as a regulating member.

In the illustrated embodiment, the pressing force F _E and / or the rotation speed U _E by means of the device 3 can be additionally adapted to the properties of the sewn material to be fed. This can take into account the fact that the displacement between the material upper layer 8 and the material lower layer 9 is determined not only by the number of revolutions n of the machine but also by the properties of the sewn material being fed and thereby in particular the friction ratios between the material lower layer 9 and the material upper layer 8. in particular friction conditions between the material upper layer 8 and the material pressing device 6.

Thus, it is essential to the invention that when the topsheet 8 and the backsheet 9 are sewn together with uneven material compression forces F as shown in FIG. 2 and resulting uneven displacement ratios, the backsheet lags behind The material 8 is compensable in that an additionally self-adjusting material feeding device 2 is provided on the material upper layer 8, in addition to the substantially conventional material feed device.

In this way, the topsheet 8 is subjected to a slight tensile stress (see FIG. 1), the amount of tensile stress being influenced by

• fc · fcfc «Fc · • fc fcfc • · fc »· Fc fc • fc • · · · fc «fc fc fc · • · • fcfc fcfc • »· · · ·

the thrust forces F _{E of the} auxiliary material feeding device 2, in that the slight přít thrust force F 1 causes a slight tensile stress in the upper material layer 8 and the associated early slipping of the auxiliary material feeding device 2; correspondingly, a higher contact force F _E causes a higher tensile stress in the upper material layer 8 and the associated later slippage of the material feeding device 2.

In this case, the tensile stress during the short-term phases of the low material compression force F (see FIG. 2) causes the upper material layer 8 to be slightly elongated relative to the lower material layer 9, thereby compensating for the otherwise occurring displacement.

In view of the method of operation and the function of the stitched material feeding device shown in FIGS. 1 to 5, it is to be considered that the displacement between the topsheet 8 and the backsheet 9 essentially occurs at the beginning of any feed phase (see FIG. 2). angle position drawbar, since in this interval the pressure of the pressing device · 6 j material as a result modalities and features of the device also feed material strengths and decreases. for this reason receives the additional device 2 for feeding a material of particular importance, because an adjustable force F _E (see 5 by which the additional material feeding device 2 presses against the material layers 8, 9, the shear in the material layers 8, 9 is influenced.

Thus, at the beginning of the feeding phase (see FIG. 2: angular position 0 _5), in which on the basis of the decreasing pressure of the thrust device 6 material formed feed material between the upper material layer 8 and the lower material layer 9, extends the delay upper material layer 8 relatively to the lower material layer 9 in the material feed direction D (see FIG. 1) and at the same time by otherwise reduced pressure of the material pressing device 6 the conditional movement of the upper layer 8 pulls out. Thus, provided that the parameters are correctly adjusted, a longer stitch without displacement between the upper material layer 8 and the lower material layer 9 can be achieved.

Additional device 2 for feeding material during the works in the low speed n _p <500 min ^_1 device 3 in the intermittent mode. In other words, the drive motor 33 (see FIG. 3) of the device 3 is in the feed phase (see FIG. 2: angle position 0a <

o <0 _E ) is switched on and off in the non-feeding phase (see Fig. 2: Angle position 0 <0 <0 ^ as well as Angle position 0 _e <0_ <2Π_). In this case, the on and off times of the device 3 are preferably

A A AA ·· • A A • A A A • A · A A A A AND AND AND • · A · • · · • AND AND AND • · • · · AND AND • A · A · · A A A A A A

are determined by the angular position 0 of the main shaft of the sewing machine 10 or the sewing machine (see FIG. 2).

Over the number of revolutions N _{of the} order of from about 500 min ^-1 is switched to the continuous drive, i.e. the auxiliary device 2 for feeding working material in the high rpm n _p> 500 min ^_1 device 3 in a continuous fashion. In this context, however, be considered that in the rpm n _p of about 500 min ¹ due to inertia and the elastic behavior of the drive members with intermittent motion besides, gradually turning into a seemingly continuous.

In this context, the passage of the material layers 8, 9 is dependent on the friction ratios between the 10 additional material feeding device 2 and the material upper layer 8 (and its properties). Also, as to that the draw ratio in the mesh material influenced by an adjustable force F _p by the auxiliary device 2 for feeding the material presses against the sewing material.

The feed path of the additional material feed device 2 is slightly larger than the feed path of the material feed device 15 per stitch forming process 15. This technical measure also ensures that the sewn material is still held under tension in the feed direction D, so that when the upper material layer 8 and the lower material layer 9 are sewn together, the displacement is prevented.

The pressing force F _{p of the} add-on material feeding device 2 and / or the rotational speed 20 n _{E of the} device 3 (-> rotation speed U _{E of the} additive material feeding device 2) are electronically controllable. For this purpose, an electronic control means 4a, 4b (see Fig. 4) for controlling the pressure force F _p of the attachment 2 for feeding material and / or the rotational speed N _{of the} device 3 (-> rotation speed U _p of the attachment 2 for feeding material ).

Since now the pressing force F _{p of the} attachment 2 and / or the rotation speed n _{E of the} attachment 3 (-> rotation speed U _{E of the} attachment 2) depends inter alia on the number of revolutions of the machine n, the machine revolutions n determined in the electronic control means 4a, 4b (see Figure 4) so that the adjustment takes place whenever the pressure force F _p of the attachment 2 for feeding material and / or the number of revolutions N _P of the 3 (-> speed of rotation of _the auxiliary apparatus 2 for material feed) speed n of the machine.

In addition, the rotation speed of _the auxiliary device 2 for feeding the material intended only machine rpm n, but among others also by the stitch length L. Since this stitch length L in the establishment of the suture 10 is mechanically adjusted, there s electronic control means 4a, 4b stitch length L mostly known. Finally, not only for this reason, the electronic control device 4a receives information about the stitch length L by inserting / via the control panel 5 (see FIG. 4). The nominal value n u u (see Fig. 4) for the speed n nMotor (see Fig. 4) of the drive motor 33 of the device 3 and thus its speed n _E , is then determined by the computer algorithm RA (see Fig. 4).

Since now the device 3 has a DC electric motor driven by 10 33 (see FIGS. 3 and 4), the rpm of the means 3 (-> speed of rotation of _the auxiliary device 2 for feeding the material) is controlled (current) regulator 4a (see FIG. 4 ). In the embodiment shown in FIGS. 1 to 5, the fact that in the drive motor 33 its speed n _E - in any case to a large extent - is directly proportional to the applied current is exploited. For this reason the speed of the drive motor nmotor I (see Fig. 4) is electronically controlled and influenced by the desired number of revolutions of the 3 I (-> desired rotational speed of _the auxiliary device 2 for feeding the material I). AND

In addition, the pressing force F _p of the material feeding device 2 is determined not only by the machine speed, but also, inter alia, between the material feeding device 2 and the top layer 8 of the sewn material acting by the frictional force. Since this frictional force is also dependent on the properties of the material to be sewn, the frictional force is generally not known to the electronic control device 4a, 4b. Finally, not only for this reason, the electronic control device 4b receives information about the properties of the sewn material to be fed by insertion via the control panel 5 (see FIG. 1).

4). The nominal value Fs _O n (see Fig. 4) for the contact force F _{p of the} add-on material feeding device 21 is then determined by the computerized algorithm RA II (see Fig. 4). AND

Since the device 3 now has a direct current driven linear motor 30 (see FIGS. 3 and 4), the contact force F _{p of the} auxiliary material feeding device 2 is controlled by the (current) regulator 4b (see FIG. 4). In the case of the embodiment I shown in FIGS. 1 to 5, the fact that in the linear motor 30 I the force F _{p is} directly proportional - in any case to I

• 0 0 · 0 · 0 00 • 0 00 • »· 0 0 0 0 • · · · • · · 0 0 9 0 • · • · · • 0 0 • · · ·· • · • 00 ·

To a large extent, the linear motor 30 is supplied with current (see FIG. 4: I _Motor ). For this reason, the current of the linear motor Ιμ _{οϊογ is} electronically controlled, and thus the required pressure of the auxiliary material feeding device 2 is influenced.

Here, the force of the linear motor 30 need not be measured. The additional material feeding device 2 is designed to be lifted from the top layer 8 of the suture material, for example so that the suture material can be removed from the suture device 10. This can also be accomplished by means of a linear motor 30, the linear motor 30 need not perform any positioning function in this context. With regard to the embodiment, features and advantages of the linear motor 30, the type of motor is fully taken into account, as described in German patent application DE 199 45 443.4 or in international patent application WO 00/18997.

In this context, both the initial value Fo and the feed rate dependent part F _p > F _- pressing forces Fo (see FIG. 5) can be appropriately parameterized and adapted, for example, via the control panel 5 (see FIG. 4) to the respective sewing conditions.

In this way, the corresponding value of the contact force F _{p can be} imitated by the equation

F _p = F _o + R n (see Fig. 5), where F _o is a constant initial value (see Fig. 5), R is the coefficient of friction which appears in Fig. 5 as the increase in the lines shown and whose size is determined friction ratios between the additional material feeding device 2 and the topsheet 8 of the material, and is the number of machine revolutions (see FIGS. 4 and 5).

From the equation F _p = F _o + R n graphically depicted in Fig. 5, it is thus clear that the pressing force F _p - besides the constant friction coefficient R and the rotational speed n of the machine independent of F _o - is essentially linear with the coefficient friction R between the additional material feeding device 2 and the material upper layer 8, and is substantially linear with the speed n of the machine.

As was already explained in the foregoing, when it is dependent on the relevant technical facts rotational speed N _E of the 3 flat rotation speed of _the auxiliary device 2 for feeding of material. Here, the speed n _{of the} device 3 is given by the equation n _p = kn · L, where k is the adaptation factor, n is the machine speed and L is the stitch length.

frfr frfrfrfr fr frfr frfr frfr • fr • • fr fr fr • fr fr • • frfr fr fr fr fr '♦ fr fr • fr frfr · • fr • • frfr frfr frfr frfrfrfr

Thus, it is apparent from the equation n _p = k · n L that the rotational speed n _{p of the} device 3 and thus the rotational speed S _{p of the} auxiliary material feeding device 2 - in addition to the subsequently specified adjustment factor k - is substantially linear with the rotational speed η 1 of the machine, and is substantially linear with the stitch length. j

The adjustment factor k is given by the equation k = ki k ₂ k ₃ , where k! is the parameter for the diameter of the attachment 2 for feeding the material for the constant of the linear and the motor 30 and the transmission ratio of 34 to ₂ is a measure for the functional dependency of the offset between the topsheet 8_materiálu and the lower material layer 9 on the machine rpm, and ₃ is a parameter properties of the sewn material to be fed.

Thus, from the equation k = kj k ₂ to ₃ , the number of revolutions n _{p of the} device 3 and hence the rotation speed U _{p of the} add-on material feeding device 2 depends on the technical conditions and assumptions of the device 3 and the add-on material feeding device 2. > factor k1), on the displacement function between the topsheet 8 of the material and the backsheet 9 through the number of revolutions n of the machine (-> factor k ₂ ), and on the properties of the sewn material being fed (-> factor k ₃ ).

From the foregoing explanations, it is clear that the device 3 plays an important role in the frame of the illustrated embodiment. In this case, its linear motor 30 has a stator element 31 designed as a housing, which is fixedly connected to a bearing plate (not shown in FIGS. 1 to 5) arranged ¹ on the rear side of the housing head of the device 10. The rotor element 32 is designed as a drive rod.

The device 3 further comprises a direct current driven drive motor 33, a transmission 34 arranged between the drive motor 33 and the additional material feeding device 2, and a transmission element 35 arranged between the transmission 34 and the additional material feeding device 35 to transfer movement to the additional material feeding device 2. .

In this connection, the device 3, in conjunction with the rotor element 32, has an anti-torsion-supported support element 36, on which the drive motor 33, gearbox 34 and transmission element 35 are secured.

 '·· ···· fc · ··· * ·· fcfc tě tě ě * tě · · ě ě ě ě ě ě

In addition, the support member 36 is biased by a spring-loaded low-weight coupling member 38 in the form of a coil spring. With regard to the embodiment, features and advantages of the coupling element 38, full account is taken of the German patent application DE 199 45 443.4 or the international patent application

WO 00/18997, in particular with respect to the coupling element 38 connected to a current-saving working method.

Claims (12)

00 »0 0 ·· 0000 0000 • 0 • · · · PATENT REQUIREMENTS ·» ···· A device for feeding 5 sewn material, provided with a sewing machine (10) or a sewing machine (10) - at least one material feed device (1) for advancing the sewn material in the material feed direction (D) at a feed rate determined by the machine speed (n) and the stitch length (L), and - at least one pressing tool-shaped topsheet (8) of sewn material Device according to claim 1, characterized in that the pressing force (F _p ) and / or the rotational speed (U _p ) is preferably adaptable by means of the device (3) to the properties of the sewn material being fed. Device according to claim 1 or 2, characterized in that the contact force (F _p ) is given by the equation Fp = Fo + Rn 30 where F is _a constant force, 4 «· · ·» • 9 9 t 9 »· 99 9 9 9 9 9, ·· · © • 9 9 • 4 9 27 Mar: • » 9 9 9 98 9 9 9 9 9 » 98 9 99 9 5 (35) and / or - which is secured, in particular by means of at least one guide rod (37), against rotation. 5 - in which the number of revolutions (n) of the machine is determined and / or which receives, in particular, information on the stitch length (L) by inserting through at least one control panel (5) (5). Device according to at least one of Claims 1 to 4, characterized in that the additional device (2) for feeding the material in the low speed range (n _p <500 min ¹ ) of the device (3) operates intermittently, wherein the on and off times In particular, the devices (3) are determined by the angular position (o) of the main shaft of the sewing device (10) or the sewing machine (10). Device according to at least one of Claims 1 to 3, characterized in that the rotational speed (n _p ) of the device (3) is a measure of the rotational speed (U _p ) of the auxiliary material feeding device (2) or equal to the rotational speed (U _p ) an additional material feeding device (2), the speed (n _p ) of the device (3) being given in particular by the equation n _p = k · n · L, wherein the adaptation factor n is the machine speed and 15 L stitch length. Device according to at least one of Claims 1 to 5, characterized in that the additional device (2) for feeding the material in the high speed range (n _p > 500 25 min ¹ ) the device (3) operates continuously. Device according to at least one of Claims 1 to 6, characterized in that the feed path of the additional material feeding device (2) attributable to the stitching process is greater, in particular slightly larger, than the feed path of the feed device (1). 30 material. Device according to at least one of claims 1 to 7, characterized in that the crossing of the pressing force (F _p ) of the additional material feeding device (2) and / or the rotational speed (n _p ) of the device (3) is arranged at least one electronic control device (4a or 4b), Device according to at least one of Claims 1 to 8, characterized in that the device (3) is provided with at least one direct current driven by a linear motor (30) which is provided in particular with at least one stator element (31) formed as a housing in which in particular, at least one is deposited as 15, a drive rod formed by a rotor element (32). • ♦ · «>> • 9 • * • ·· # 9 9 ' 9 • • • · · • · 9 9 9 • • • • 9 9 • • • 99 9 99 ·· 9999 R is a coefficient of friction, the magnitude of which is determined by the frictional ratios between the material feeding device (2) and the material upper layer (8) and n is the machine speed. Device according to claim 4 and claim 9, characterized in that the adjustment factor (k) is given by the equation 20 k = kf k ₂ · k ₃ , where k is the parameter for the diameter of the add-on device (2) for the material feed, for the constant of the linear motor (30) and for the transmission to the low-speed transmission (34), 25 k ₂ scale for functional dependence of the feed between the upper material layer 8 and the lower material layer 9 on the machine speed (n) and k ₃ parameter for the properties of the sewn material to be fed. 10 with a pressing force (F _p ) acting and a rotation speed (U _p ) rotating, an additional material feeding device (2) arranged downstream of the material feed device (1) in the material feed direction (D) and proportional to the speed (n) machines and movable to the stitch length (L), characterized in that by means of at least one device (3) 15 - the contact force (F _p ) exerted by the auxiliary material feeding device (2) on the top layer (8) of the sewn material being fed is increased with increasing speed (n) and / or the rotational speed (U _p ) of the auxiliary device (2) ) for material feeding is in addition to the proportional increase with increasing machine speed (n) still 20 further magnifiable. Apparatus according to claim 9 and claim 10, characterized in that the device (3) is provided with at least one supporting element (36) standing with the rotor element (32), - on which the drive motor (33), the gearbox (34) and the transmission element are mounted Device according to claim 11, characterized in that the support element (36) is biased by means of at least one springing low-mass connection element (38), in particular by means of at least one coil spring.