US3266084A - Apparatus for the hot stretching of threads and especially of synthetic textile filaments - Google Patents

Description

3,266,084 APPARATUS FOR THE HOT STRETCHING OF THREADS AND Aug. 16, 1966 x. THERY ESPECIALLY OF SYNTHETIC TEXTILE FILAMENTS Filed Sept 10, 1964 2 Sheets-Sheet 1 //v VIVTOR X The!" y ATTORNEYS Aug. 16, 1966 x, THERY 3,266,084

APPARATUS FOR THE HOT STRETCHING OF THREADS AND ESPECIALLY OF SYNTHETIC TEXTILE FILAMENTS Filed Sept 10, 1964 2 Sheets-Sheet 2 //Vl/E/VTOR X. The r y WM ATTOR NE Y5 United States Patent 3,266,084 APPARATUS FOR THE HUT STRETCHHNG 0F THREADS AND ESPECHALLY 0F SYN- THETIC TEXTILE FILAMENTS Xavier Thery, 132 Rue dYpres, Wambrechies, France Filed Sept. 10, 1964, fier. No. 395,435 Claims priority, application France, Sept. 11, 1963, 947,224 3 Ciairns. (Cl. 18-1) It is well known that, in contradistinction to natural textile fibers, synthetic fibers having a polyester or polyamide base exhibit, when stretched, not only a substantial elasticity which prevents maximum utilization of their great resistance to rupture and wear, but also a permanent elongation which results in unacceptable deformations.

It has already been suggested that this elasticity be reduced by subjecting the synthetic filaments to a controlled stretching process carried out at a precise temperature.

This treatment which is especially necessary in the case of sewing thread, threads for filters, sieves, or silk-screening processes, synthetic cloths made from continuous filaments, etc., has the effect of orienting its molecules and reducing its elasticity, while retaining its dynamometric strength.

The present invention relates to an apparatus which permits the above mentioned treatment to be carried out in an advantageous manner.

This invention consists of a new machine which comprises a stretching device which is used especially for synthetic filaments and fibers. This device is characterized essentially by its use of the combination of a cylinder heated to a constant temperature and provided with peripheral grooves in each of which a filament lies, and two feedingdevices placed upstream and downstream of said drum, the proportion between the tangential speeds of the feeding devices being a function of the elongation sought, and the tangential speed of the drum being preferably in between the tangential speeds of the feeding devices.

The present invention also has as its object a feeding device which may be used advantageously with the stretching device defined above, this feeding device being characterized essentially by the fact that it comprises a row of rings having biconical surfaces, so that fibers placed between two consecutive rings are wedged between these rings.

In the method of construction preferred for the feeding device according to the invention, the rings have at one point on their peripheries a slit which permits the easy cutting of any filament which has become wound up on the feeding device as a consequence, for example, of an accident.

In order to clearly explain the invention there will now be described by 'way of illustration and without limiting the scope of the invention to the details thereof, one embodiment, taken as an example and illustrated on the accompanying drawings, in which:

FIG. 1 shows schematically a stretching device conforming to the invention;

FIG. 2 is a longitudinal sectional view of a feeding device conforming to the invention;

FIG. 3 is a section taken along the line IIIIII of FIG. 2; and

FIG. 4 is a partial axial section through the drum.

As may be seen on the drawing, the stretching device according to the invention consists essentially of the drum 1 and feeding devices 2 and 3 respectively, placed upstream and downstream of the drum, and a take-up cylinder assuring that the filaments will follow around the greater part of the periphery of the drum.

The filaments 5 are formed into a layer parallel to one another by comb 6 and are directed to feeding device 2 over take-up cylinder 7.

Feeding device 2 leads the filaments at a constant speed over take-up cylinder 4. The filaments then pass over drum 1, after which feeding device 3 brings them up to its own speed.

Finally, after having passed over take-up cylinder 8 and over the guides 9, the fibers pass over an oiling roller 10, to be then wound on the reels in the usual manner.

As may be seen in FIG. 4 where it is shown cut in half, drum 1 is mounted on the free end of shaft 11 by means of a spider 12 provided formed with a plurality of apertures.

The wall of the drum is constructed of a metal which is a good heat conductor, for example, copper, and its periphery is provided with annular grooves having a substantially triangular section. For example the bottoms of these grooves may be 6.5 mm. apart when the grooves are 4 mm. deep.

Such a device permits filaments 5 to be isolated perfectly from one another while they are wound about the drum.

The drum is heated by four gas burners 13, 14, 15 and 16 which are mounted parallel to each other inside the drum.

From the time that the device is turned on until the desired temperature is reached, valve 17 is left open so that the four burners 13, 14, 15 and 16 function simultaneously. When the operating temperature is reached and a great heating power is therefore no longer necessary, valve 17 is closed by hand so as to cut off burners 13 and 14, only burners 15 and 16 being then supplied from the gas inlet pipe 13 through electrically operated valve 19.

An auxiliary pipe 20 is provided with a valve 21 through which the burners are supplied at a low rate when the electrically operated valve is closed, so that the temperature may be regulated as will be explained below.

To control the electrically operated valve 19, an expansion gauge 22 is placed in the wall of drum 1, the electric conductors of which device are connected to the electrically operated valve 19 by brushes 23 positioned on the rear face of the drum.

Thanks to this device, when the drum reaches a predetermined temperature, the expansion gauge acts on valve 19, which closes, thus drastically decreasing the heating power of burners 15 and 16 which are then supplied only at a low rate through the auxiliary pipe 20.

inversely, when the temperature of drum 1 drops below the set temperature, electrically operated valve 19 opens and burners 15 and 16 again function normally.

The gases produced by the combustion in burners 13, 14, 15 and 16 escape on each side of the hollow drum. This escape is made possible by openings in the spider 12 which connects the drum to shaft 11.

Gas heating is not essential and other sources of heat, such as electricity, are compatible with the invention.

Taking account of the fact that the drum rotates and that it is made of .a metal which is a good heat conductor, it is possible to obtain a high degree of precision in the regulation of the temperature which is transferred to the filaments, which, as is well known, is essential to the successful thermal treatment of the filaments.

The device may be improved upon by adding an intermediate cylinder, driven independently of the drum, between the flame and the drum carrying the threads, so as to avoid partial overheating of the drum, and consequent deterioration of the threads, in case the machine is stopped for a substantial length of time, to repair broken threads, for example.

As may be seen on FIGS. 2 and 3, the feeding means according to the invention consists of a shaft 24 supporting a row of biconical rollers 25 fixed to the shaft 24 by a key 26.

These rollers are held on the shaft by the nut 27, which permits the feeding device to be easily disassembled whenever cleaning is necessary. The scraps of thread which accumulate between the rollers may thus be easily eliminated.

As seen best on FIG. 2, the rollers 25 are biconical in section, so that the end portions 25a taper more sharply toward the center than the portions 25b.

Consequently, when a thread is wound on the feeding device between two rollers, it automatically positions itself between adjacent portions 25b, as shown at the top of FIG. 2.

It follows that the thread is positively gripped by the feeder, so that the speed of the feeder is imparted to the thread.

In accordance with the invention the rollers 25 are provided with a slot 28 at one point along their peripheries. These slots register with each other to form a groove running the full length of the feeder.

These slots 28 make it possible to readily cut any thread which has become accidentally wound around the feeder by introducing a cutting tool into the slots.

Such an accident may happen Whenever a thread breaks unexpectedly, since each thread is gripped between two feeder rollers.

The fact that threads thus wound up on the roller may be easily cut makes it possible to get the machine back in operation promptly.

The applicant has made and extensively tested a machine which gives complete satisfaction and has the following characteristics:

It permits 60 threads to be treated simultaneously, the heating cylinder has a diameter of 55.5 cm. and it is provided with 60 triangular grooves spaced 6.5 mm. from center to center and 4 mm. deep. As has previously been explained, the cylinder projects from a spider provided with 8 openings, and its inner diameter is about 35 cm. It is driven at a speed which may be controlled by a dc vice known as a horses head.

The stretching devices consist of a stack of 61 disks so shaped that, when they are brought up against each other, the angle between the adjacent faces which are to grip the thread is 9".

The stretching devices are driven from the shaft which drives the drum through two variable speed transmissions so that if the drum is considered to turn at a speed of 100 units, the speed of the feeding device upstream of the drum may be varied between 84 and 100 units and that of the feeder downstream of the drum at between 100 and 128 units.

During the heating period the drum is driven at a reduced speed by an auxiliary motor at the rate of about one revolution every five minutes, so that the drum will be uniformly heated.

With means such as that which has been described for regulating the temperature of the drum, this temperature 4 is maintained within a range of about plus or minus 1.5 C.

For example, continuous filament nylon of 210/2 deniers (21,500 meters/kg.) has been treated on this machine at a speed of 41 meters/minute, so that the machine handles about 6.9 kg. of material per hour.

Continuous filament tergal of 250/3 deniers (10,600 meters/ kg.) has also been treated at a speed of 26 meters/ minute, so that the machine handled 8.8 kg. of material per hour.

Discontinuous tergal fibers of 88/3 deniers (31,000 meters/kg.) have also been treated at a speed of 72 meters/ minute, so that the machine handled about 8.3 kg. of material per hour.

It will of course be appreciated that the embodiments which have been described were given purely by way of example and may be modified as to detail without thereby departing from the basic principles of the invention.

In particular, it is obvious that the specific heating means does not constitute an essential feature of the invention and other heating means may be substituted therefor.

Similarly, the feeding devices which have been described, while especially suited for use with the stretching device of the invention, may also be replaced by other types of feeding means.

What is claimed is:

1. A device for stretching textile threads, said device comprising a heated rotatably mounted drum provided with a plurality of peripheral grooves for receiving said threads, rotatably mounted guiding means for said threads positioned upstream and downstream of said heated drum, and means for rotating said drum and guiding means at different speeds with the downstream guiding means turning at a tangential speed greater than and the upstream guiding means at a tangential speed less than that of said drum, each guiding means comprising a row of parallel discs which touch each other at their central portions, the principal surfaces of said discs sloping away from said central portions so that threads led between said discs are gripped thereby.

2. A device as claimed in claim 1 in which the discs of each guiding means are removably mounted on a central pin.

3. A device as claimed in claim 1 in which said discs are provided with registering transverse notches which define a recess parallel to said pin for receiving a knife.

References Cited by the Examiner UNITED STATES PATENTS 1,962,028 6/1934 Murphy et al. 2,307,056 1/ 1943 Minich 264-288 2,745,134 5/1956 Collins 18-1 3,095,606 2/1963 Scott 181 X FOREIGN PATENTS 833,756 4/1960 Great Britain.

37/12,7l1 9/1962 Japan.

WILLIAM J. STEPHENSON, Primary Examiner.

Claims (1)

1. A DEVICE FOR STRETCHING TEXTILE THREADS, SAID DEVICE COMPRISING A HEATED ROTATABLY MOUNTED DRUM PROVIDED WITH A PLURALITY OF PERIPHERAL GROOVES FOR RECEIVING SAID THREADS, ROTATABLY MOUNTED GUIDING MEANS FOR SAID THREADS POSITIONED UPSTREAM AND DOWNSTREAM OF SAID HEATED DRUM, AND MEANS FOR ROTATING SAID DRUM AND GUIDING MEANS AT DIFFERENT SPEEDS WITH THE DOWNSTREAM GUIDING MEANS TURNING AT A TANGENTIAL SPEED GREATER THAN AND THE UPSTREAM GUIDING MEANS AT A TANGENTIAL SPEED LESS THAN THAT OF SAID DRUM, EACH GUIDING MEANS COMPRISING A ROW OF PARALLEL DISCS WHICH TOUCH EACH OTHER AT THEIR CENTRAL PORTIONS, THE PRINCIPAL SURFACES OF SAID DISCS SLOPING AWAY FROM SAID CENTRAL PORTIONS SO THAT THREADS LED BETWEEN SAID DISCS ARE GRIPPED THEREBY.

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