Patent Application
20150152596
The invention pertains to a device for producing a strand or a cable, especially a wire strand or a wire cable, which device comprises a rotatable arrangement for feeding cords to a twisting point, at which the cords are twisted around each other, and an installation for heating at least one of the cords. The invention also pertains to a method for producing the strand or the cable.
In a device of this kind known from prior use, wire strands are guided. to the twisting point by way of a rotating twisting basket, where they are twisted around a core strand coated with plastic and thus pressed into the plastic material. To heat the plastic and thus to soften it, gas burners are provided, which are directed at the core strand. So as not to interfere with the rotational movement of the strands, these burners are arranged outside the area upstream of the twisting point, i.e., the area through which the rotating wire strands and the core strand are guided on their way to the twisting point. The disadvantage is that a relatively large area must be heated to soften the plastic, for which a large amount of energy is required.
The invention is based on the goal of creating a device of the type indicated above by means of which operations can be carried out in a more energy-efficient manner.
According to the invention, this goal is achieved in that the heating installation is rotatable along with the feed arrangement.
As a result of the invention, it becomes possible to arrange the heating installation within the above-mentioned area in which the rotating strands are guided to the twisting point.
As a result, the heat produced by the heating installation can be focused on the strand which is to be heated. Only a relatively small area needs to be heated, and thus less energy is consumed than is the case with the known device. This solution also prevents the device itself, especially the twisting basket and possibly a preform head of the feed arrangement, from being heated at the same time.
Additional advantages may also be mentioned. In the case of the known device, the amount of heat which the gas burners can produce to heat the core strand is limited by the need to prevent the rotating wire strands being fed to the twisting point from becoming so strongly heated along with the core strand that their mechanical properties are impaired. In the device according to the invention, however, the heat is focused, which means that the strand forming the core can be heated more strongly without the danger that the other strands will undergo significant heating. Especially when one of the strands is coated with plastic, as described above, and this strand must be softened for the sake of the cable-making process, the stronger heating of the plastic means that the softening can be conducted more quickly and that it is possible in turn to twist the strands at a faster speed.
Because, furthermore, the device according to the invention makes it possible to control the heating of the strand more effectively, it is also possible to make use of this heating to subject the strand to a stress-relief annealing prior to the twisting process and thus to achieve better mechanical properties. The service life of the strand or cable can thus be increased.
In an especially preferred embodiment of the invention, the heating installation is set up to heat the cord intended to form the core strand or core cable. In one embodiment the invention, furthermore, the heating installation, which advisably comprises a burner for fuel, preferably a gas burner, and/or an electrically operated heating installation, preferably a heating resistor, an infrared radiator and/or an induction coil, and/or a device for supplying hot air, is arranged in the free spaces formed between the cords leading to the twisting point. Alternatively or in addition, the heating installation can also be provided to heat the cords provided for the formation of the outer strands. This is found to be especially advantageous in cases where the heating installation of the device can be used to heat each of the cords used to produce the wire strand or wire cable in a controlled manner and thus to relieve their stress.
In another embodiment of the invention, the heating installation for direct heating is set up only for the cords intended to form the outer wire strands. The cords can be heated in such a way that they are so hot at the twisting point that, on contact with the plastic, they are pressed into the plastic as it softens, wherein the plastic becomes plastically deformed.
For the production of the strand or cable, furthermore, several of the cords, especially also the cords intended to form the outer strands, are coated with plastic, and the heating installation can be used to heat the plastic on each cord to its softening point. As a result, it becomes possible to arrange the cords in the cable or strand more homogeneously in the plastic. In one embodiment of the invention, only the cords provided to form the outer strands are coated with plastic. These become embedded in the plastic of the wire cable, and the plastic can form an outward-facing sheath around the wire cable.
It is advisable for the heating means to be arranged rotatably on the feed arrangement or on a mounting device attached to a base. Whereas it would also be conceivable to provide a separate drive to rotate the heating means on the mounting device in synchrony with the rotational movement of the feed arrangement, the heating means, in a preferred embodiment of the invention, is connected to the feed arrangement preferably by struts, so that the heating means rotates along with the feed arrangement.
The operating medium required to operate the heating means, especially electrical energy, heated air, or fuel, can be supplied by way of a bearing, by means of which the heating means is rotatably supported on the mounting device.
Alternatively, the heating means could also be permanently attached directly to the feed arrangement, especially to the twisting basket or to the preform head, line of the heating means, by means of which the fuel or electrical energy can be supplied, is in this case advisably also arranged on the feed arrangement, preferably in the previously mentioned free space, or is guided through the feed arrangement. The required energy or fuel is advisably fed by way of a bearing, by means of which the feed arrangement is rotatably supported in the device.
In the preferred embodiment, an empty space is provided between the stationary part and the rotatable part of the bearing to supply the fuel; the fuel is to be conducted through this space. The stationary part of the bearing is advisably connected to a fuel source, whereas the rotatable part is connected to the burner. It is obvious that the empty space is sealed off against the outside, preferably by means of a sliding ring seal or a contactless seal, to prevent uncontrolled escape of the fuel.
To transmit the electrical energy from the stationary part to the rotatable part of the bearing, means for sliding contact are advisably provided, which are connected on one side to an energy source and on the other side to the previously mentioned line. The electrically operated heating means can be thus be supplied continuously with current.
In an elaboration of the invention, a generator is provided to provide energy for the electrically operated heating installation; this generator is preferably set up to act as a dynamo to recover energy directly from the rotational movement of the feed arrangement. The transmission of the electrical energy via the bearing is then no longer necessary.
In a preferred embodiment of the invention, the heating means is provided with thermal insulation means, which preferably comprises a shielding. As a result of this thermal insulation, the heat can be focused more effectively; the heating of the environment can be avoided more completely; and energy can be conserved more efficiently. It has been found especially advantageous for the thermal insulation to be provided in such a way that it surrounds in a tubular manner the cord to be heated.
The invention is explained in greater detail below on the basis of exemplary embodiments and the attached drawings, which refer to the exemplary embodiments:
During the production of a wire cable 30, a core cable 3, which is provided with a plastic sheath, and wire strands 4, which are preformed by means of the preform head 2, are supplied via the preform head 2 to a twisting point 5, and, under rotation of the preform head 2 around its longitudinal axis, twisted to form the wire cable 30.
A mounting device 8 for a heating installation 1 is mounted on the carrier body 21; the heating installation comprises five gas burners 6, which are directed toward the core cable 3 and to which gas can be supplied via gas lines 22. The mounting device 8 comprises a rotary bearing 10, which comprises a fixed outer ring 13 and a inner ring 14, which rotates in the outer ring 13. The inner ring 14 is connected to the preform head 2 or to a shaft 25 driven by the preform head by way of struts 24 (shown only in
The empty space 15 is formed between two ball bearings 18, 19 and extends around the entire circumference of the rotary bearing 10. It is sealed off against the outside by a contactless seal 17, such as a throttle seal, especially a throttle gap seal or a throttle labyrinth seal, or by an air purge seal or a slip ring seal, so that gas supplied through the line 20 can flow through the empty space 15 to the burners 6 via the gas lines 22 provided on the inner ring 14 of the rotary bearing 10.
In the production of the wire cable 30, the inner ring 14, the gas lines 20, and the burners 6 rotate in synchrony with the preform head 2, wherein the fuel gas is conducted through the feed gas line 20 to the empty space 15 in the rotary bearing 10 and from there through the lines 22 to the burners 6. As is especially clear from
The wire strands 4 are heated by the burners 6 to only a minor extent.
Because the heating installation 1 according to the invention makes it possible to control the heating temperature effectively, the device according to the invention can also be used to anneal the core cable 3 and possibly the wire strands 4 to relieve their internal stresses during the twisting process. As a result, the mechanical properties of the cable 30 thus produced are improved. For this purpose, additional gas burners (not shown) aimed directly at the wire strands 4 could also be provided.
It would also be conceivable to provide gas burners which are aimed only at the wire strands 4 and to heat the wire strands 4 in such a way that they heat the plastic sheath around the core cable 3 at the twisting point 5 in such a way that they are pressed into the plastic sheath as the plastic softens.
As can be seen in
The electrical energy required to heat the heating resistor 7 is supplied via electrical lines 20b, which are guided along the brackets 24b to the rotary bearing 10b and transferred across the rotary bearing 10b by means of the sliding contact shown in
During the production of a wire cable, the heating resistor 7 and the brackets 24b rotate along with the preform head 2b during the twisting process. It is supplied with electrical energy via the electrical lines 20b, 22b and the sliding contact.
In another exemplary embodiment (not shown), at least one induction coil, instead of a heating resistor 7, is arranged around the core cable 3b to heat the core cable 3b by induction.
Alternatively or in addition to the previously mentioned means for heating the core cable 3, 3b, it would also be possible to provide an infrared radiator and/or a line through which hot air could be directed onto the core cable.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2012 105 817.2 | Jul 2012 | DE | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/DE2013/100243 | 7/2/2013 | WO | 00 |
