MXPA00010021A - Cable guide roller, synthetic fibre rope suitable therefor and their use - Google Patents

Abstract

The turn-round unit for a twisted synthetic fiber cable (3) comprises a turn-round element (5) which accommodates at least three cable twist lengths (17) over a wrap angle (18). Also claimed is a twisted synthetic fiber cable suitable for use with a turn-round element (5). It is characterized by the fact that diameter of the turn-round element and the cable twist length are chosen so that the above mentioned condition is satisfied.

Description

Change of direction of cable and synthetic fiber cable suitable for it, as well as its use Description The invention relates to a change in the direction of the cable and to a synthetic fiber cable suitable for this purpose, with the characteristics indicated in the preamble of claims 1 and 2, as well as its use. The cables constitute in the technique of transport, for example in the case of elevators, the construction of cranes and in mining and the like, an important mechanical element subjected to strong stresses. A cable, when running under load on a change-of-direction element, such as a cable roll, a cable pulley or a cable drum, etc., is bent over the change-of-direction element, which leads to Special movements of the cord cords. For example, EP 0 6782 781 Al discloses a cable used correspondingly. The multilayer cable of aramid fiber strands twisted in parallel offers very satisfactory values in terms of useful life and high resistance to abrasion and alternating flexion. However, it has been found that when changing the direction of the synthetic fiber cable with permanent load on a drive pulley, a cable drum or a cable pulley or the like, in a short period of service cable deformations can occur in the form corkscrew in the area of traction of the outer layer of cords, which could lead to a reduction in the resistance to breakage of the cable or even failure thereof. Therefore, the invention aims to specify a cable direction change with lasting reliability with a synthetic fiber cable running on a roll or drive pulley. This object is solved according to the invention by means of a cable direction change with the characteristics indicated in claim 1, characterized in that the synthetic fiber cable rests on the direction change element at least along a length of three wiring steps. The subclaims contain improvements and / or convenient and advantageous embodiments of the invention indicated in claim 1. Therefore, the essence of the invention consists in that the diameter of the change of direction element and the wiring step of the synthetic fiber cable they are coordinated to each other in such a way that, when the cable embraces the change-of-direction element, each of the cords of the outer layer rests at least three times on it. Extensive tests of the applicant have shown that the smaller the arc of arc and the greater the wiring step of the outer layer of ropes, the more bead is dragged when bending on a roll of cable, a cable pulley, a cable drum or Similar. The smaller the wiring step and the greater the change of direction element, the smaller are the relative movements of the cords to each other. This shows that the smaller the wiring step of the outer layer, the smaller the diameter of the cable roll, the drive pulley or the like can be. According to the invention, it has been found that, as a minimum requirement, when the cord embraces the drive pulley it must be supported on it at least three times in order to reliably avoid irreversible cord displacement. In a refinement of the invention, it was found that, in a cable drive, the less the drive cord is supported on the bottom of the groove of the driven rope pulley, the easier it is that excess lengths occur in the area of the rope. traction. As is known, the operation of these cable drives is based on the fact that the driving force is applied to the cable through the section thereof which is in contact with the drive pulley. The cable is bent when driving on the drive pulley, so that, especially in the area of tension of the outer layer of strands, the missing length is sucked in correspondingly. At the same time, the drive pulley mainly pushes the cords of the cable pressure area. The internal compensation of the cable system is especially important to satisfy these multiple cable solicitations.

Therefore, according to a preferred embodiment of the invention, in a cable drive with synthetic fiber with intermediate jacket, the formation of excessive lengths in the traction area is avoided if the diameter of the drive pulley and the passage of The cables are coordinated with each other in such a way that the cords of the outer layer rest at least four times on the drive pulley. In this form of cable with intermediate jacket, the excess lengths in the traction area are less reversible the higher the coefficient of friction between the intermediate jacket and the outer layer of cords, since the cords under load of cable are subject to the clamping force. In the following, a preferred embodiment of the invention will be described in detail based on the drawings. The drawings show: Figure 1. A schematic view of a change of cable direction in an elevator installation with a cab attached to a counterweight through synthetic fiber cord cables according to the invention. - Figure 2. A schematic representation of a cable with twisted cords. - Figure 3. A view of a cable pulley in the direction of the axis of rotation and a braided drive cable according to the invention. According to FIG. 1, a cab 2 circulating in a housing 1 is suspended from several, in this case six, drive cables 3 of support aramid fibers, which run on a drive pulley 5 connected to a drive motor 4. On the booth 2 there are cable end connections 6 in each of which one end of one of the cables 3 is fixed. The opposite ends of the cables 3 are fixed in the same way to a counterweight 1, which also circulates through the cable. box 1. The compensation cables 9 are similarly connected with their first end to the lower end of the car 2. The compensation cables 9 are guided to the lower part of the counterweight 7 by means of an investment pulley 11 arranged on the ground 10 of the box and aligned under the place of fixing on the floor of the cabin, and an investment pulley 12 also mounted on the box floor 10 and facing the counterweight 7, and are articulated in said lower part of the counterweight 7. The The compensation cables 9 are tensioned longitudinally between the car 2 and the counterweight 7 with the help of weights or, as shown here, by the pulley 12. In this case, a traction spring 13 is used, which is anchored to the wall of the vehicle. box and strip of the reversing pulley 12 towards said wall, whereby tensioning the compensation cables 9. Instead of the tension spring, the reversing pulley 12 can also be provided with a suitable kinematics for tensioning the compensation cables.

The drive pulley 5 has six adjacent grooves 8 disposed very close to each other, each for a drive cable 3 that is twisted according to the invention and described below. So far, in the construction of elevators are common motor pulleys with two to twelve slots. In the embodiment described here, the grooves 8 are configured with semicircular profile. However, other groove shapes that are known to the person skilled in the art and can be provided in accordance with the cross-sectional shapes of the cable used in each case can also be used, without however modifying the essence of the invention. To define concepts, figure 2 shows by way of example a synthetic fiber cable 31 of three strands of aramid fiber 14 twisted in torsion Z in a manner known per se. The aramid cords 14, 15, 16 are closely arranged one next to the helical shape, following the direction of passage, essentially the central part of the letter "Z". The length of the braid pitch is indicated by the example of the aramid cord 16 marked in black and is designated as the wiring step 17. In addition to the example shown here, the designations can be transferred to the synthetic fiber cables 3 of various layers of the target. the invention, in which the advantages that can be achieved with the teaching of the invention increase the greater the number of layers of cords. The direction of torsion of individual cord layers is of secondary importance. Rather, for the invention, the succession of layers of cords with different torsional sense, mainly those adjacent to the outer layer of cords, is essential. In case of use of synthetic fiber cables with intermediate jacket between the layers of individual strands, the excess lengths dragged in the traction area of the curved cable are less reversible the higher the coefficient of friction between the intermediate jacket and the outer layer of laces, since the cord dragged under the cable load is held by the clamping force. According to the invention, the following rule can be applied: the greater the coefficient of friction between the intermediate mesh and the outer layer of cords, the more often a bead of the outer layer must be supported on the drive powder when it embraces it. Figure 3 shows the cable pulley 5 and a drive cable 3 corrugated by it representing the various cables 3 commonly used. The cable 3 is connected at one end to the car 2 and at the other end to the counterweight 7, by means of which mass forces said cable 3 is permanently loaded 3 while driving on the cable pulley 5. The load of car 2 and the counterweight 7 ensures a sufficient frictional connection between the drive pulley 5 and the cable section which rests in each case on the drive pulley 5 along the clamping angle 18. In this embodiment of a cable drive according to invention, the diameter 20 of the drive pulley measures 260 mm. Accordingly, the wiring passage 17 of the outer cord layer can not be longer than 60-80 mm In this way, according to the invention, a minimum clamping angle of 120 ° can be used. A clamping angle of 180 ° is shown in Figure 3. However, a clamping angle of 140 ° is also customary, as is envisaged, for example, in the embodiment according to FIG. 1. With this type of embodiment it is ensured that the cable, when driving on the motor pulley, rests on it along an arc of embrace whose length corresponds to more than three steps of wiring 17 of the braided drive cable 3. In addition to applications such as pure lift cable, the cable can be used in the most diverse installations of the transport technique , for example for elevators, extraction facilities for mining wells, construction cranes, cranes for ships or cranes for ships, funiculars and ski lifts, and as a means of traction in escalators. The drive can take place either by friction bonding through drive pulleys or Koepe pulleys, or by cable drums on which the cable is wound. Transport cable means a cable driven in motion, which is also sometimes referred to as a tension or lift cable.

List of reference numbers 1. Box 2. Cabin 3. Drive cable 3 ' . Drive cable 4. Drive motor . Drive pulley 6. Cable end joint 7. Counterweight 8. Cable grooves 9. Compensating cable 10. Box floor 11. Inversion pulley 12. Inversion pulley 13. Tension spring 14. Aramid fiber cords . Aramid fiber cords 16. Aramid fiber cords 17. Wiring step 18. Bracket angle 19. Contact point 20. Motor pulley diameter

Claims (10)

R E I V I N D I C A C I O N S

1. Change of cable direction, in which a twisted synthetic fiber cable, consisting of at least synthetic support fiber strands twisted in an outer strand layer, is guided in a circular arc on a direction change element, characterized in that the synthetic fiber cable rests on the change of direction element at least along an angle of embrace equivalent to three wiring steps.

2. Changing the cable direction according to claim 1, characterized in that the direction change element has at least one profiled groove on which a cable of synthetic fiber cords is supported, the cords of the outer layer being supported at least three times in the bottom of the slot.

3. Changing the cable direction according to claim 1 or 2, characterized in that the cable of synthetic fiber cords is supported on the change-of-direction element along an angle of embrace defined by a circular arc of 120 ° to 180 °. ° inclusive.

4. Cable direction change according to one of claims 1 to 3, characterized in that the diameter of the direction change element is greater than 250 mm.

5. Change of cable direction according to one of claims 1 to 4, characterized in that the synthetic fiber cable has an outer layer of cords with a wiring pitch of 60-80 mm.

6. Synthetic fiber cable for running on a direction change element on which the cable can be guided according to a circular arc, consisting at least of strands of synthetic fiber support braided in an outer layer of cords, characterized in that the diameter of the direction change element and a wiring step of the synthetic fiber cable are coordinated with each other in such a way that, at an angle of engagement, each of the cords of the outer layer rests at least three times on the element of change of address.

7. Synthetic fiber cable according to claim 6, characterized in that the outer layer of strands has a wiring pitch of 60-80 mm. Synthetic fiber cable according to claim 6 or 7, characterized in that it consists at least of strands of synthetic support fiber, which are braided together forming two layers of concentric strands, and an intermediate jacket formed between the layer of inner strands and the outer lacing layer. Synthetic fiber cable according to one of claims 1-9, characterized in that the synthetic fiber support cords consist of aromatic polyamides. 10. Cable drive with a cable direction change according to one of the claims 1-5.