Apparatus for Regulating Fiber Quantities Supplied to a Textile Machine

This invention relates to an apparatus for regulating the supply of fiber quantities to a textile machine, particularly the quantities of fiber in a fiber lap fed to a card or a roller card unit (hereafter collectively referred to as a carding machine). The apparatus includes a measuring device extending over the width of a fiber layer surface for mechanically sensing the thickness deviations at several locations along the width. The sensed signals are, prior to comparing them with a predetermined desired value, combined by a mean value forming arrangement and, as a function of the deviation of the measured actual (mean) value from the desired value, the fiber quantity to be supplied to the textile machine is altered.

In a known apparatus of the above-outlined type excursions of levers connected with side-by-side arranged lap supporting trays represent thickness variations at several locations across the width of the fiber lap. The deflections of the individual levers are combined by means of a lever system and processed mechanically. Such a system, however, is structurally complex and its accuracy is inherently limited.

It is an object of the invention to provide an improved apparatus of the above-outlined type wherein the accuracy of the fiber quantity regulation is improved in a structurally simple manner.

This object and others to become apparent as the specification progresses, are accomplished by the invention, according to which, briefly stated, upon thickness deviation of the fiber material supplied to the textile machine, the sensed individual mechanical signals are transformed into individual electrical signals which are electrically added to produce a combined electric signal.

By converting mechanical signals into electric signals, deviations in the fiber lap to be supplied to a carding machine may be measured in a structurally simple manner. Further, an electric processing of the measuring signals makes possible shorter response periods for the control or regulation of a setting member so that the accuracy (degree) of the fiber quantity regulation is significantly increased.

FIG. 1 is a schematic side elevational view, including a block diagram, of a preferred embodiment of the invention.

FIG. 2 is a schematic side elevational view, including a block diagram, of another preferred embodiment of the invention.

FIG. 3 is a schematic front elevational view of components illustrated in FIG. 2.

FIG. 4 is a schematic side elevational view, including a block diagram, of still another preferred embodiment of the invention.

FIG. 5 is a block diagram showing details of a component illustrated in FIG. 4.

Turning now to FIG. 1, there is shown a feed chute 1 of a pneumatic fiber tuft delivering apparatus which is connected to a carding machine generally indicated at A. At the lower end of the feed chute 1 there are arranged two feed rollers 2 and 3 underneath which there is situated an arcuate support table 4 which changes the substantially vertical orientation of a fiber lap 5 delivered by the rollers 2 and 3 to a substantially horizontal orientation. Downstream of the support table 4 there is arranged a lap feeding device formed of a feed roller 6 and a feeding table 7. Downstream of the feeding arrangements 6, 7 (as viewed in the direction of lap advance) there is arranged a lickerin 8 and a cylinder 9 of the carding machine A.

Between the support table 4 and the feed table 7 there are provided a plurality of tray levers 10 situated closely side-by-side across the width of the fiber lap 5. The orientation and shape of the tray levers 10 are of significance: they engage the fiber lap from below, underneath a stationarily arranged, rotatable and, if desired, driven support roller (counter roller) 11, providing for a reliable grasping of the fiber tufts between the tray levers 10 on the one hand and the support roller 11 on the other hand. Each tray lever 10 is secured to one end of a lever arm 11 rotatable about a pivot 12 which is arranged approximately in the middle of the lever arm. The lever arm 11 is loaded (biased) at its other end by a weight 13 or a spring. Between the pivot 12 and the weight 13 each lever arm 11 carries an armature 14 which cooperates with a solenoid 15. Each solenoid 15 is connected to a common mean value forming device 16 which, in turn, is connected to an electric delay device 17 such as an integral member and a regulator 18 known by itself. The delay device 17 may also be associated with the I-part (integrating part) of the regulator 18. The latter is connected with a drive motor 19 of the feed roller 6 of the carding machine.

During operation, thickness deviations of the fiber lap 5 are mechanically sensed at several locations by means of the individual tray levers 10 arranged across the width of the upper surface of the fiber lap 5. The individual mechanical signals are, by means of the armatures 14 and the associated solenoids 15 (functioning as transducers) converted into individual electric signals which, by means of the mean value forming device 16 are electrically added to form a combined electric signal (mean value). The combined signal is, with a delay effected by the delay device 17 applied to the regulator 18 and, after a comparison with a predetermined desired value, the rpm of the drive motor 19 of the feed roller 6 is altered (error compensation) so that more or less fiber material in the fiber lap is supplied to the carding machine. The mean values may be also integrated over time for compensating for long-wave errors.

Turning now to the embodiment illustrated in FIG. 2, there is provided a measuring member 20 having a convex support face oriented towards the support roller 11. On the convex support member 20 there is mounted a resistor 21 which is engaged by a compression spring 22 having a stationary support on its other end. With the resistor 21 there is associated a wiper arm 23 which is connected with the mean value forming device 16 which in turn is connected to the regulator 18. The latter sets the desired rpm of the drive motor 19 for the feed rollers 2 and 3 of the feed chute 1.

Turning now to FIG. 3, there are shown closely juxtapositioned measuring members 20a through 20h which, by means of springs 22a through 22h press the fiber lap 5 against the support roller 11. The width of each measuring member 20a through 20h may be, for example, 60 mm and they may number, for example 18.

According to FIG. 4, the regulator 18 is connected to the input of an rpm coupling element 28 which, in turn, is connected to electronic motor regulators 24 and 25 which may be SIMOREG model rpm setters, manufactured by Siemens AG, Munich, Federal Republic of Germany. The motor regulators 24 and 25 are connected to rpm-variable drive motors 26 and 27 such as d.c. motors. As shown in FIG. 5, the rpm coupling element 28 has two potentiometers 29 and 30 connected to the electronic motor regulators 24 and 25, respectively, and also connected to the regulator 18. By means of the potentiometers 29, 30 the electronic motor regulators 24 and 25 can be separately set.

It is to be understood that it is within the scope of the invention to provide a measuring member above the fiber lap 5 in contradistinction to the embodiments described where the sensors are arranged underneath the fiber lap.

It will be understood that the above description of the present invention is suceptible to various modifications, changes and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims.