DE1243599B - Device for weaving machines with removal of the weft thread from stationary bobbins for sucking in an approximately úŽ-shaped loop in a weft thread - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. CI:

Number:
File number:
Registration date:
Display day:

D03d

German class: 86 c-14/05

N19433VII a / 86c
January 16, 1961
June 29, 1967

In modern weaving machines, which work at a very high speed, the application a looper reciprocable through the shed is impossible, the weft becomes blown into the compartment with air. The problem arises that the thread is not directly from a stationary bobbin can be withdrawn because the thread overcome too great a resistance would have to. So a thread of a certain length is to be drawn off the truncated cone-shaped bobbin, and this thread is to be drawn in and stored in some way in such a way that this length is immediately can be released without the thread having to overcome too great a resistance.

According to an older proposal (German patent specification 1224214), a device is used for this purpose for weaving machines with removal of the weft thread from stationary bobbins for sucking in a approximately U-shaped loop in a weft thread in the open end of a shaft of slot-shaped Cross-section with an enlargement at each end of the slit-shaped cross-section, which The shaft is connected at its other end to a suction system that can be shut off by a valve, so that when the valve is open, the weft thread that is passed by can be sucked in in the form of a chain and when the valve is closed Valve, the loop can easily be pulled out of the shaft without a suction effect being exerted on it is.

There are certain difficulties in that the air at the time when the suction valve is closed to adjust the suction effect in the shaft is still in motion, and due to their kinetic energy, the air is in the closed suction valve in the closed end of the shaft slightly compressed.

This now requires that the compressed air in the interior of the shaft then dissolves expands again and a kind of rebound occurs due to the elasticity properties of the air.

Immediately after the suction effect is set, a kind of air oscillation is thus obtained, the one pushes back the loop of the weft thread formed in the form of a rear indentation. This through Pushing back a loop caused by the rebound of the air can now become a tangle Result in the thread being crossed over.

The invention is based on the object of avoiding these disadvantages. In a device for looms according to the older proposal, this is essentially achieved in that two devices for looms with removal
the weft thread from stationary bobbins
for sucking in an approximately U-shaped loop
in a weft

Applicant:

N. V. Machinef abriek L. te Strake,

Deurne (Netherlands)

Representative:

Dipl.-Ing. H. Marsch, patent attorney,

Düsseldorf, Lindemannstr. 31

Claimed priority:

Netherlands of January 22, 1960 (247 629)

see the open end of the stem and the valve an air valve communicating with the outside air is arranged. Through this air valve is the natural frequency of a pressure wave produced by the closing of the valve that can be shut off from the suction system increased in the shaft, so that the air column can not get into resonance and the dreaded air oscillation does not come fully to training and, insofar as it comes to training, still through the Effect of the air valve is dampened.

According to a further feature of the invention, the air valve can be removed from the valve that can be shut off the suction system be arranged at such a distance that the period of the occurring by the closing of the valve Pressure wave is about a quarter of the original period, which is caused by the length of the shaft is determined. This measure achieves particularly effective damping of the pressure wave.

In the drawing, the subject matter of the invention is shown using an exemplary embodiment. It shows

Fig. 1 is a plan view of a shaft for suction a loop in a thread,

F i g. 2 shows a longitudinal section of the shaft along the line II-II of FIGS. 1 and

Fig. 3 shows a cross section along the line III-III of Fig. 2.

The shaft A is located on the side edge of the loom to the side of the shed. One of the shaft A along running thread is at the open end 1, if the thread is not stretched, pulled with a loop in the shaft A, because at

709 608/146

Claims (2)

A suction opening 2 is located at the end of the shaft A. The suction opening 2 can be shut off by means of a valve 3 and is connected to a suction system via a line 4. The shaft Λ consists of a flat cavity 5 with a slit-shaped cross-section, which has an enlargement 6 on each of its two sides (FIG. 3). The housing which forms the shaft A consists of a lower half 7 and an upper half 8. The upper half 8 is preferably made of transparent material so that the loop of the thread, when it is in the shaft A, is visible, which is desirable, for example, when the loom is at a standstill, e.g. B. to restore a weaving defect or a broken thread. In part 7 there is a channel 9, the passage of which can be closed by an air valve 10. The duct 9 communicates with the outside air via a valve housing 11 and a passage 12 when the air valve 10 is closed. While the loop in the thread is sucked in, the valve 3 is open and the thread passes through the open end 1 in the form of a loop into the shaft A. The roughly parallel threads of the loop lie in the extensions 6. As soon as the thread is back is pulled out of the shaft A, the valve 3 closes so that no more air can enter through the open end 1 of the shaft A and the suction ceases. As soon as the valve 3 is closed, the air valve 10 opens, so that the length of the shaft A is suddenly interrupted in connection with the resonance of the air column. The air valve 10 can also be opened a short while before the valve 3 closes. In order to bring about the influence of the air valve 10 with the associated channel 9 in the direction of the propagation of the pressure wave in the shaft A, the channel 9 comes on the point where it opens into the shaft A, in this in the form of a slot. By opening the air valve IO, a good damping of the pressure wave occurring when the valve 3 is closed is achieved, without side effects due to the deflection of the reflection and buffer effect, through which the thread could possibly get out of its correct position. Patent claims: 1. Device for weaving machines with removal of the weft thread from stationary bobbins for sucking an approximately U-shaped loop in a weft thread into the open end of a shaft of slot-shaped cross-section, each with an extension at both ends of the slot-shaped cross-section, which shaft at its other end at. a suction system that can be shut off by a valve is connected so that when the valve is open the weft thread can be sucked in in the form of a loop and when the valve is closed the loop can easily be pulled out of the shaft without any suction being exerted on it, characterized in that between the open end (1) of the shaft (A) and the valve (3) an air valve (10) connected to the outside air is arranged. - 2. Apparatus according to claim 1, characterized in that the air valve (10) from the valve (3) is arranged at such a distance that the period of the pressure wave occurring by the closing of the valve (3) is about 'a quarter of the original Period, which is determined by the length of the shaft (A \ . _: , Considered publications:
German Patent No. 1224214.. 1 sheet of drawings 709 608/146 6.67 © Bundesdruckerei Berlin