The present invention relates to a metal cable.
Metal cable is frequently used in brake assembly of bicycle or motorbike. Metal cable is used for activating brake clamp when user grabs and presses handle of the brake assembly. Conventionally, metal cable is manufactured by twisting several metal wires. To obtain batter operation performance, metal cable which has lowered friction, minimized elongation, and greater flexibility is desired.
To reduce friction caused in operation, metal cable, as disclosed in
Additionally, some metal cables, as disclosed in
Another metal cable, as described in
The present invention is, therefore, arisen to obviate or at least mitigate the above mentioned disadvantages.
The main object of the present invention is to provide a metal cable which is prepared for batter operation performance in brake assembly.
To achieve the above and other objects, a twisted cable according to claim 1 is provided including a central wire and several surround wires.
The surround wires are arrenged around the central wire. The surround wires are arranged in layers which are concentrically defined outwardly from the central wire as an inner layer, a middle layer, and an outer layer.
The surround wires are classified according to sizes of areas of transversal cross sections thereof, and classified into first wires, second wires, third wires, and fourth wires, which are ranged from the smallest to the largest. Each transversal cross section of each surround wire is perpendicular to an axial direction of the surround wire.
The inner layer comprises six second wires. Size of area of transversal cross section of each second wire is smaller than the size of area of transversal cross section of the central wire.
The middle layer comprises plural first wires and plural third wires. The third wires are interspersed between any two adjacent first wires of the first wires. Quantity of the first wires of the middle layer, quantity of the third wires of the middle layer, and quantity of the second wires of the inner layer are the same.
The outer layer comprises plural fourth wires. Quantity of the fourth wires of the outer layer is equal to the total quantity of the first wires and the third wires of the middle layer.
Each of the fourth wires has an inner surface facing the central wire and an outer surface away from the central wire. Curvature of the outer surface is smaller than curvature of the inner surface from a cross sectional viewpoint. The surround wires are twisted on the central wire together.
The present invention will become more obvious from the following description when taken in connection with the accompanying drawings, which show, for purpose of illustrations only, the preferred embodiment(s) in accordance with the present invention.
Please refer to
The wires of the twisted cable 1 include a central wire 11 and several surround wires. The surround wires are arranged around the central wire 11. The surround wires are arranged in layers which are concentrically defined outwardly from the central wire 11 as an inner layer, a middle layer, and an outer layer. In other words, the inner layer is located between the central wire and the middle layer, the middle layer is located between the inner layer and the outer layer, and these three layers are defined circularly and annularly in transversal cross section. The surround wires are classified according to sizes of areas of transversal cross sections thereof, in particular, are classified into first wires 12, second wires 13, third wires 14, and fourth wires 15 by ranging the surround wires from the smallest to the largest, wherein each transversal cross section of each surround wire is perpendicular to an axial direction of the surround wire. In other words, the first wires 12 have the smallest cross section in the surround wires. Cross sections of the first wires 12, the second wires 13, and the third wires 14 are preferably formed circularly before entwisting or pressing.
The inner layer includes several second wires 13 which are annularly arranged. Cross section of the second wire 13 is smaller than cross section of the central wire 11. Therefore, there are six second wires 13 in the inner layer. Given that the cross section of the second wires 13 is smaller than the cross section of the central wire 11, gaps are defined and remain between the second wires 13.
Preferably, ratio of radius of contour of cross section of each second wire 13 to radius of contour of cross section of the central wire 11 is equal to or greater than 0.8. Thus, the inner layer includes just six second wires 13.
The middle layer includes several first wires 12 and several third wires 14. The first wires 12 and the third wires 14 are annularly arranged. The third wires 14 are interspersed between any two adjacent first wires 12. Therefore, the third wires 14 and the first wires 12 are alternatively arranged. Quantities of the first wires 12 and the third wires 13 are equal to quantity of the second wires 12 of the inner layer respectively. In the present embodiment, first, second, and third wires are all six wires, and are eighteen wires in total. The sizes of areas of transversal cross sections of the third wires 14 are equal to size of area of transversal cross section of the central wire 11 respectively. Each third wire 14 is adjacent to two second wires 13, and each first wire 12 is adjacent to one second wires 13. Thus, the third wires 14, which are larger than the first wires 12, are held in the recesses between any two adjacent second wires 13.
The outer layer includes several fourth wires 15 which are annularly arranged. Quantity of the fourth wires 15 is equal to total quantity of the first wires 12 and the third wires 14. In the present embodiment, the middle layer includes six first wires 12 and six third wires 14. Thus, there are twelve fourth wires 15 in the outer layer. Preferably, each fourth wire 15 is located adjacent to one first wire 12 and one third wire 14. Thus, the fourth wires 15 are held in or adjoined to the recess between one of the first wires 12 and the adjacent third wire 14. Each fourth wire 15 has an inner surface 151 and an outer surface 152. From a cross sectional viewpoint, curvature of the outer surface 152 is smaller than curvature of the inner surface 151. That is to say, in comparison with the inner surface 151, the outer surface 152 is smoothened. From the cross sectional viewpoint, contour of the outer surface 152 is an arc, as shown in
In addition, as shown in
To take structure strength, weight, and thickness in consideration, the wires may be manufactured in the sizes below:
However, the sizes mentioned above are not made unchangeable. Sizes of the wires can be magnified or shrunk by a predetermined scale.
Accordingly, the twisted cable 1 has smoothened outer surface. Friction and abrasion caused in pulling are minimized. When the twisted cable 1 is assembled in brake assembly, resistance caused in pulling the twisted cable is minimized, too. Thus, handle of brake assembly can pull the twisted cable dexterously and precisely.
In addition, the wires of inner layer and middle layer are arranged around the central wire 11. Interval vacant space is reduced. Thus, elongation of the twisted cable is also reduced.
Moreover, internal space is remained between the middle layer and the outer layer. Thus, the twisted cable can be bent or curved easily. Fitting for bicycle or motorbike is facilitated.
This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.