DESCRIPTION OF THE DRAWINGS
The above, as well as other advantages of the present invention, will become readily apparent to those skilled in the art from the following detailed description of a preferred embodiment when considered in the light of the accompanying drawings in which:
FIG. 1 is a cross-sectional view of the construction of a tensile carrier according to the present invention;
FIG. 2 is a schematic illustration of a supporting and drive means with the tensile carriers of FIG. 1;
FIG. 3 shows a variant embodiment of a supporting and drive means with at least two tensile carriers according to FIG. 1;
FIGS. 4 and 4A are an example of an embodiment of a supporting and drive means with a triple-layered tensile carrier per rib according to the present invention;
FIGS. 5 and 5A are an example of another embodiment of a supporting and drive means with a double-layered tensile carrier per rib;
FIGS. 6 and 6A are an example of an embodiment of a supporting and drive means with two triple-layered tensile carriers per rib; and
FIGS. 7 and 7A are an example of embodiment of a supporting and drive means with two double-layered tensile carriers per rib.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The following detailed description and appended drawings describe and illustrate various exemplary embodiments of the invention. The description and drawings serve to enable one skilled in the art to make and use the invention, and are not intended to limit the scope of the invention in any manner. In respect of the methods disclosed, the steps presented are exemplary in nature, and thus, the order of the steps is not necessary or critical.
FIG. 1 shows the construction of a tensile carrier 1. The tensile carrier 1 comprises several strand layers, an outer strand layer 2, a first inner strand layer 3, a second inner strand layer 4 and a core layer 5. A sheathing is denoted by 6. Construction and diameter of the strands 7 of the outer strand layer 2 are the same. The first inner strand layer consists of, in diameter, larger strands 8 and smaller strands 9. The larger strands 8 approximately correspond in diameter with the strands 10 of the second inner strand layer 4 and the core layer 5. The strands 7 of the outer strand layer 2 are larger in diameter than the larger strands 8 of the first inner strand layer 3 and the strands 10 of the second inner strand layer 4. The larger strands 8 of the inner strand layers 3, 4 are larger in diameter than the smaller strands 9 of the first inner strand layer 3. The larger strands 8 of the first inner strand layer 3 and the strands 10 of the second inner strand layer 4 are approximately the size in diameter as the core layer 5. The strands 10 of the second inner strand layer 4 are stranded around the core layer 5, the strands 8, 9 of the first inner strand layer 3 are stranded around the second strand layer 4 and the strands 7 of the outer strand layer 2 are stranded around the first inner strand layer 3.
A strand 5, 7, 8, 9, 10 consists of stranded threads, which in turn consist of unstranded or unidirectional synthetic fibers. The tensile carriers 1 can be built up from chemical fibers such as, for example, aramide fibers, Vectran fibers, polyethylene fibers, polyester fibers, etc. The tensile carrier 1 can also consist of one or two or more than three strand layers.
FIG. 1 shows the tensile carriers in which the strands of a strand layer are mutually spaced apart. The spacing between two strands 7 of the outer strand layer 2 is denoted by d1. The spacing between two strands 8, 9 of the first inner layer 3 is denoted by d2. The spacing between two strands 10 of the second inner strand layer 4 is denoted by d3. d1 can lie in the range of, for example, 0.05 millimeters to 0.3 millimeters and d2 and d3 in the range of 0.01 millimeters to 0.08 millimeters.
With the mutual spacing, the strands 7 of the outer strand layer 2 can move in radial direction r in the direction of the cable center and exert a radial pressure on the strands 8, 9 of the first inner strand layer 3. The radial pressure is passed on by the strands 8, 9 of the first inner strand layer 3 to the strands 10 of the second inner strand layer 4. The radial pressure is passed on by the strands 10 of the second inner strand layer 4 to the core layer 5. The radial pressure increases inwardly from strand layer to strand layer.
Should the strands 7, 8, 9, 10 of the respective strand layer hit against one another as seen in circumferential direction Ur, the traction forces could not be transferred from the strands 7 of the outer strand layer 2 to the strands 8, 9 of the first inner strand layer 3 or from these to the strands 10 of the second inner strand layer 4 and further to the core strand 5.
FIG. 2 shows a schematic illustration of a supporting and drive means 11 with at least two tensile carriers 1 according to FIG. 1, which extend axially parallel to the longitudinal axis of the supporting and drive means. The supporting and drive means 11 has the geometry of a flat belt consisting of a belt body 12 or sheathing 12, which encloses the tensile carriers 1 or in which the tensile carriers 1 are embedded. The belt back is denoted by 13. The running surface of the belt can be flat and parallel to the belt back 13 or, as illustrated in FIG. 2, have trapezium-shaped ribs 14 and grooves 15, which run axially parallel to the tensile carriers 1, wherein the profile of the drive pulley or the deflecting pulley is matched to be approximately complementary to the profile of the running surface 16 of the belt 11. A drive pulley or a deflecting pulley form in conjunction with the belt 11 a force lock. One tensile carrier 1 is provided per rib 14, wherein the tensile carriers 1 are laid or stranded alternately in the “Z” direction and the “S” direction. Instead of the trapezium-shaped ribs 14 shown in FIG. 2, semicircular ribs could also be provided. In a cogged belt the ribs 14 and grooves 15 run transversely or obliquely relative to the tensile carriers 1. Drive pulley or deflecting pulley in conjunction with the belt 11 form a shape lock.
As explained above and as illustrated in FIG. 3, the tensile carriers 1 in the belt 11, 111 are laid or stranded in alternation in the “S” direction and the “Z” direction. The strands 7 of the outer strand layer 2 are laid in the same direction as the strands 8, 9 of the first inner strand layer 3 or are laid the same as the strands 10 of the second inner strand layer 4. The lay direction of the strands of one strand layer can also be different relative to the lay direction of the strands of the other strand layer. The tensile carrier 1 is then no longer stranded in equal lay as illustrated above, but in reverse lay, also termed cross lay. For example, the strands 7 of the outer strand layer 2 can be stranded in the “S” direction and the strands 8, 9 of the first inner strand layer 3 in the “Z” direction and the strands 10 of the second inner strand layer 4 again in the “Z” direction. Tensile carriers stranded in reverse lay are neutral in torque.
FIG. 3 shows a supporting and drive means 11 with at least two tensile carriers 1 according to FIG. 1, which extend axially parallel to the longitudinal axis of the supporting and drive means. The supporting and drive means 11 have the geometry of a double cable 11 consisting of a cable body 112 or sheathing 112, which encloses the tensile carriers 1 or in which the tensile carriers 1 are embedded. The left-hand tensile carrier 1 is laid in the “Z” direction and the right-hand tensile carrier 1 is laid in the “S” direction. Each tensile carrier comprises several strand layers 2, 3, 4, wherein the strands 7, 8, 9, 10 forming the strand layer are stranded (helical twisting around one another of strands of a strand layer about the strand layer lying thereunder). Synthetic fibers are bundled to form a thread, wherein several threads are stranded in the “S” direction or the “Z” direction to form a strand.
The double cable 111 can, together with the sheathing 112, be constructed as a flat cable or flat belt or have a narrowing 113 between the tensile carriers 1. In the variant with the narrowing 13 the common running surface 116 of the double cable 111 together with the drive pulley is formed, as seen in cross-section, from in each instance approximately a semicircle of the tensile carrier 1 and half the narrowing 113. The profile of the drive pulley or of a deflecting pulley matches the profile of the running surface 116 of the double cable 111 in approximately complementary manner. In addition, more than two tensile carriers 1 can also be encased by a common sheathing and form a multiple cable with or without narrowing 113 between the tensile carriers 1.
The sheathing 112, which is much softer by comparison with the strands 7, extends approximately to the first inner strand layer 3 and has no influence on the mutual supporting of the strand 7. The soft sheathing 6 does not act in circumferential direction Ur as a support between the strands 7. The strands 7 of the outer strand layer 2 are in a position of moving radially inwardly. The sheathing material can, for example, lie in the Shore hardness range 75 A to 95 A and the matrix material of the strands 7 or the matrix of the strands 7 can, for example, lie in the Shore hardness range of 50 D to 75 D.
FIGS. 4 and 4A show an example of embodiment of a supporting and drive means 11 with a triple-layered tensile carrier 1 per rib 14 in accordance with FIG. 1. As explained above, the tensile carriers 1 are laid or stranded alternately in the “Z” direction and the “S” direction. The size of the supporting and drive means 11 and the size of the tensile carrier diameter and the strand diameter are indicated in millimeters in FIG. 4A.
FIGS. 5 and 5A show an example of embodiment of a supporting and drive means 11 with one double-layered tensile carrier 1 per rib 14. The outer strand layer 2 has been omitted. Accordingly, strands with larger diameters have been used. As explained above, the tensile carriers 1 are laid or stranded alternately in the “Z” direction and the “S” direction. The size of the tensile carrier diameter and the size of the strand diameter are indicated in millimeters in FIG. 5A. The diameter of the tensile carrier 1 according to FIG. 5 and the diameter of the tensile carrier 1 according to FIG. 6 are identical. The diameters of the comparable strands are different.
The supporting and drive means 11 according to FIGS. 4 and 5 has, for a width of 48 millimeters, a yield force of 60 kN to 90 kN and is suitable for a drive pulley diameter or deflecting pulley diameter equal to or greater than 90 millimeters. The ratio of the pulley diameter “D” to the tensile carrier diameter “d” is also to be taken into consideration, for example D/d lies in the range of 16 to 45, as well as the desired service life and the desired number of bendings of the supporting and drive means.
FIGS. 6 and 6A show an example of embodiment of a supporting and drive means 11 with two triple-layered tensile carriers 1 per rib 14 according to FIG. 1. As explained above, the tensile carriers 1 are laid or stranded alternately in the “Z” direction and the “S” direction. The size of the tensile carrier diameter and the size of the strand diameter are indicated in millimeters in FIG. 6A.
FIGS. 7 and 7A show an example of embodiment of a supporting and drive means 11 with two double-layered tensile carriers per rib 14. The outer strand layer 2 has been omitted. Accordingly, strands with larger diameter have been used. As explained above, the tensile carriers 1 are laid or stranded alternately in the “Z” direction and the “S” direction. The sizes of the tensile carrier diameter and the strand diameter are indicated in millimeters in FIG. 7A. The diameter of the tensile carrier 1 according to FIG. 7 and the diameter of the tensile carrier 1 according to FIG. 8 are identical. The diameters of the comparable strands are different.
The tensile carriers 1 of FIGS. 6 and 7 have a substantially smaller diameter than the tensile carriers 1 of FIGS. 4 and 5.
The supporting and drive means 11 according to FIGS. 6 and 7 have, for a width of 48 millimeters, a yield force of 60 kN to 90 kN and are suitable for a drive pulley diameter or deflecting pulley diameter equal to or greater than 90 millimeters. Also to be taken into consideration are the ratio of the pulley diameter to the tensile carrier diameter and the desired service life or the desired number of bendings of the supporting and drive means.
In accordance with the provisions of the patent statutes, the present invention has been described in what is considered to represent its preferred embodiment. However, it should be noted that the invention can be practiced otherwise than as specifically illustrated and described without departing from its spirit or scope.
Patent Application
20080081721
