DE7727443U1 - DEVICE FOR MEASURING THE FORCE ACTING ON A NEEDLE HEAD DURING A KNITTING OR KNITTING PROCESS - Google Patents

Description

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Dipl..ing. η. MITSCHErIkJh ': · i:' ··: ·: ': "d.sooo Munich 22

Dipl.-Ing, K. GUNSCHMÄSjN '""' 'Stelnsdorfstrasse 10

Dr.r. ,, net. W. KÖRBER '^ ^{(089 >> 2} ' ⁶⁶⁸⁴

Dipl.-Ing. J. SCHMIDTEVERS
PATENT LAWYERS

Dr. IUA SISKO PIETIKÄINEN

Rauduntie 11 H.

02130 Espoo 13, Finland

Device for measuring the forces acting on a needle head during a knitting or warp knitting process

The invention relates to a device for measuring the forces acting on a needle head during a knitting process works.

The stress a yarn is subjected to during knitting depends on the properties of the used Yarn, the structure and setting of the knitting machine used, the stitch structure of the knitted fabric to be produced as well as environmental influences.

The stress or the tension of the yarn is related to the more or less great ease with the knitting can be carried out, i.e. with a low tension, the yarn can be processed easily, and the operation of the knitting machine is seldom interrupted, and vice versa.

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3s are already different devices for the Hessen forces involved in knitting have been proposed. This includes a device of high sensitivity Measuring the drive torque of a stocking knitting machine, which is arranged on the drive shaft of the machine. the Measurement results obtained with the aid of this device can be mathematically converted into those for knitting the yarn convert required work (Textile Research Journal, Vol. 37 (7), 1967, p. 539).

The above known device provides an overall measurement result, i.e. it does not provide any information about the changes in the tension of the yarn to be processed or through tension peaks, which are of great importance with regard to the continuity of the knitting process. The The same applies to a device that is also already known, in which a complete knitting lock is provided by a force transducer arrangement (Journal of the Textile Institute, Vol. 61 (7), 1970, p. 340).

These disadvantages of the known devices have already led to the development of various devices for measuring the forces acting on one needle only.

In such a device, strain gauges for generating signals corresponding to the forces occurring are arranged between the separate needle head and the needle butt so that the impulse generated by the force acting on the needle head is transmitted to the needle butt via the extensometer (knitting and Strickereitechnik, Vol. 18 (6), 1968, p. 309). This device is designed so that it can only be used on flat knitting machines with a large needle pitch (3 gg).

Numerous other known attempted solutions are based on the measurement of the forces which the needles act on the cams of the rope lock. In a known device, the knitting cam is the knitting cam fixed, connected to the force converter (Textile Research Journal,

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Vol. 33 (6), 1963, p. 532), and in another known The device are both the knitting cams and the cams arranged underneath. on the force transducer or Transducer attached (Journal of the Textile Institute, Vol. 67 (4), 1976, p. 113). These known devices allow it to study the forces exerted by a needle on the cams when associated with the one Needle foot a separate cam track is available, the cams provided with the transducer being the one to be examined Guide the needle in the associated cam path while all | Move the remaining needle feet along another cam track.

Furthermore, a device has already been proposed in which a part of the loop formation cam by a the carrier attached to the Keßwertwandler is replaced (Sen-I Gakkaishi, Vol. 24 (2), 196S, p. 18).

When trying to measure the yarn tension during a knitting process with the help of the forces generated by a needle are exerted on the cams of the knitting lock, there is a large distance between the measuring point and the to examining part of the yarn. Hence the measurement result influenced not only by the forces acting on the needle head, but by several other factors.

The latest in thread tension measurement in knitting it seems to correspond to a device in which a section (verge) at the upper end of the needle cylinder is replaced by a plate attached to the transducer (Journal of the Textile Institute, Vol. 67 (4), 1976, p. 199). This method can be used on machines with only one set of needles. In this process, the Forces are measured when the needle is pressed down by the thread onto the top of said section be applied. The tension of the yarn forming a new stitch forms only a small part of the result.

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The invention is based on the Aufgr'a that arise in the to avoid the above-described known devices resulting limitations and disadvantages.

According to the invention, this object is achieved by the device Protection claim resolved. This ensures that measurement results are delivered that are in addition to those on the needle head acting forces are only influenced by a few additional factors that information about the effective Forces supplied during the entire movement of the needle and that the proposed device can easily be used in circular knitting machines can be installed in different designs.

An embodiment of the invention is explained in more detail below with reference to schematic drawings. It shows:

Fig. 1 to illustrate the installation of a device according to the invention in the needle cylinder of a circular knitting machine a radial partial section of the needle cylinder wall; and

Fig. 2 shows the external view of part of the needle cylinder wall ^,! which is provided with an opening.

The arrangement shown in FIGS. 1 and 2 includes a needle cylinder wall 1, a needle guide groove 2, webs 3 between adjacent needle guide grooves and a latch needle 4 with a needle head 5 and a needle flow 6; furthermore are Strain gauge 7, lines 8 for transmitting the strain gauge pulses so / ie an opening 9 is present in the needle cylinder wall.

The device of Fig. 1 is in the needle cylinder a Circular knitting machine installed in the manner described below. The strain gauges that come into effect as force measuring gobes 7 are fastened according to FIG. 1 to the shaft of the needle 4 with the aid of glue. The needle cylinder wall 1 is close to the needle 4 belonging guide groove 2 with

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Provide an opening y, the height of which is slightly larger than the up and down travel distance of the needle, and its width e.g. equal to the sum of the width of the needle guide groove 2 and is the total width of the two walls or webs 3 adjacent to it. Thus there is sufficient leeway for the strain gauges 7 and the lines 3 for transmitting the pulses are present.

The lines 8 are connected to an amplifier which is attached to the inner surface of the needle cylinder wall 1 can, so that the amplified pulses are fed to a recording device down through the lower end of the needle cylinder can be. The amplifier and the recorder are not shown in the drawing.

Since the strain gauges 7 are arranged on both sides of the shaft of the needle 4, they will otherwise be on a Deflection of the needle is eliminated, so that only the longitudinal forces acting on the needle are correct be measured.

If all the needles of the knitting machine work in the same way, it is sufficient to have strain gauges 7 on only one Attaching a needle; if the knitting machine has needles with different tasks, as is often the case with the If so, strain gauges are preferably attached to a needle of each group in question.

In the embodiment shown, the opening has 9 for receiving the lines 8, a height which corresponds essentially to the up and down movement distance of the needle 4, and in order to create sufficient clearance, parts of the adjacent webs 3 are completely cut away. That inside directed end of the opening 9 can be given smaller dimensions, and the lines S can be fixed in the opening be that the free length of the lines between the attachment point and the strain gauges 7 is sufficient to an unimpeded up and down movement of the needle 4 to er.-rjglichon. To get the necessary leeway for the strain gauge

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7x \. create, it is also possible to only partially remove the webs 3 adjacent to the bot-hitting groove 2.

Although the invention is described above with regard to its application in the needle cylinder of a circular knitting machine, but it should be noted that it can also be used with needle beds and, in particular, with dials.

The patent attorney:

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Claims (1)

I · a t.a «ι ι 14 4 1 I f I Dipl..Ing. H. MITSCHERliJCSH ,,! ' Il ' Ί ' ί j D; 8000 MONKS 22 Dipl. -Ing. K. GUNSCHMANN Steinsdorfstrasse 10 Dr.rrnat. W. KÖRBER * ^{(β9) <Ϊ966Β4} Dipl.-Ing. J. SCHMIDY-EVERS PATENT LAWYERS ⁵ September 1977 Dr. IUA SISKO ΡΙΕΤΙΚΛ'ΙΝΕΝ Rauduntie 11 II 02130 Espoo 13, Finland CLAIM Device for measuring the forces acting on a needle head during a knitting or V7irkvorgangs at a Knitting or warp knitting machine, to which a needle bed or dial with needle guide grooves belongs and in which needles are arranged in the guide grooves, each having a head, a shaft and a foot, thereby geken that at least two strain gauges (7) on surfaces of the shaft facing away from one another at least one needle (4) between the loading head (5) and the needle butt (6) are attached that in the range of motion of the strain gauges at least a part of the walls (3) the associated needle guide groove (2) on both sides of the needle has been removed in order to achieve a sufficient To create room for the extensometer, and that the needle bed or dial in the range of motion the strain gauge is provided with an opening (9) for connecting a device for forwarding the to allow pulses generated by the strain gauges to be sent to the strain gauges. 7727443 12/29/77