Patent Publication Number: US-2022215987-A1

Title: Cable

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to a cable, and more particularly to a low-loss and high-speed signal cable used to transmit high-frequency signals. 
     2. Description of Related Arts 
     With the rapid development of big data and the Internet of Things, the demand for high-speed and high-frequency signal cables has grown rapidly. However, in the process of high-frequency and high-power signal transmission, cables are susceptible to interference from external electromagnetic signals and cannot guarantee stable and effective signal transmission. 
     Therefore, it is necessary to provide a high-speed signal cable with low loss, high transmission rate, good bending resistance, and simple manufacturing. 
     SUMMARY OF THE INVENTION 
     A main object of the present invention is to provide a high-speed signal cable with low loss, high transmission rate, and good bending resistance. 
     To achieve the above-mentioned object, a cable comprises a pair of wires including two inner conductors and a respective insulating layer covering each of the two inner conductors; a first shielding layer covering the pair of core wires; a second shielding layer covering the first shielding layer; and an outer coating layer covering the second shielding layer, wherein the insulation layer is covered with a sheath layer that is simultaneously extruded and formed, and the sheath layer covers the core wires so that the two core wires abut each other in parallel. 
     Compared to prior art, the present invention has the advantage that the cable conductor spacing is smaller, making the structure more compact. At the same time, the cable has good shielding effect and good bending resistance. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         FIG. 1  is a cross-sectional view of a first embodiment of a cable of the present invention; 
         FIG. 2  is a cross-sectional view of a second embodiment of the cable of the present invention; 
         FIG. 3  is a cross-sectional view of a third embodiment of the cable of the present invention; 
         FIG. 4  is a cross-sectional view of a fourth embodiment of the cable of the present invention; 
         FIG. 5  is a cross-sectional view of a fifth embodiment of the cable of the present invention; 
         FIG. 6  is a cross-sectional view of a sixth embodiment of the cable of the present invention; 
         FIG. 7  is a cross-sectional view of a seventh embodiment of the cable of the present invention; and 
         FIG. 8  is a cross-sectional view of an eighth embodiment of the cable of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIG. 1  shows the first embodiment of a cable  100  of the present invention. The cable  100  includes a core wire  10 , a first shielding layer  15  covering the core wire  10 , and a second shielding layer  16  covering the first shielding layer  15 . Two ground wires  18  are arranged between the first shielding layer  15  and the second shielding layer  16  and an outer coating layer  17  covering the second shielding layer  16 . 
     In this embodiment, the core wire  10  includes two wires abutting each other in parallel and extending in the longitudinal direction. The core wire  10  includes two inner conductors  11 , and the two inner conductors  11  are separately covered with an insulating layer  12 , the insulating layer  12  is covered with a sheath layer  13  which is simultaneously extruded and formed. The sheath layer  13  compactly wraps the core wire  10 , so that the two core wires abut in parallel, which can effectively reduce the attenuation in the signal transmission process, and at the same time, further enhance the anti-twisting performance, greatly reducing and dispersing the torsion stress on the core wire, and prolongs the service life of the cable. It should be noted that there are air gaps between the insulating layer  12  and the sheath layer  13 , and there are also air gaps between the first shielding layer  15 , the ground wire  18  and the second shielding layer  16 . 
     The inner conductor  11  is selected from the group including a pure copper conductor, a silver-plated copper conductor, and a tin-plated copper conductor. The insulating layer  12  is made of any one or a mixture of two of polyethylene, polypropylene, polyperfluoroethylene propylene, foamed polyethylene, Foamed polyperfluoroethylene propylene, and polytetrafluoroethylene. The sheath layer  13  is made of any one or a mixture of two of polyethylene, polypropylene, polyperfluoroethylene propylene, foamed polyethylene, Foamed polyperfluoroethylene propylene, and polytetrafluoroethylene. 
     The first shielding layer  15  is spirally wound or longitudinally wraps the core wire  10 . The coating method of transverse winding will have seams between adjacent windings, so compared to the coating method of transverse winding, the shielding effect of spiral winding or longitudinal coating is better. The first shielding layer  15  is selected from the group including hot-bonded aluminum foil, pure aluminum foil, double-sided aluminum foil, heat-bonded copper foil, pure copper foil, and double-sided copper foil. The second shielding layer  16  is spirally wound or longitudinally wraps the first shielding layer  15 . The second shielding layer  16  is selected from the group including hot-bonded aluminum foil, pure aluminum foil, double-sided aluminum foil, heat-bonded copper foil, pure copper foil, and double-sided copper foil. The second shielding layer  16  increases the thickness of the entire shielding layer and increases the shielding effect. At the same time, the two-layer shielding layer also enhances the bending resistance of the cable. 
     The outer coating layer  17  is made of hot-bonded PET (polyethylene terephthalate), which is spirally wound in different directions to cover the second shielding layer  16  to make the cable structure more stable. The ground wire  18  is arranged at the left and right ends of the outer side of the first shielding layer  15 , and is located on the extension line of the center line of the inner conductor  11 . 
       FIG. 2  shows the second embodiment of the cable of the present invention. Compared with the first embodiment, there is no air gap between the sheath layer  13  and the insulating layer  12  in this embodiment, and the others remain unchanged. 
       FIG. 3  shows the third embodiment of the cable of the present invention. Compared with the first embodiment, the ground wire  18  is not provided in this embodiment, and the others remain unchanged. 
       FIG. 4  shows the fourth embodiment of the cable of the present invention. Compared with the second embodiment, the ground wire  18  is not provided in this embodiment, and the others remain unchanged. 
       FIG. 5  shows the fifth embodiment of the cable of the present invention. Compared with the first embodiment, the insulating layer  12  of the core wire  10  is directly covered by the first shielding layer  15 , and there is no sheath layer  13  between the insulating layer  12  and the first shielding layer  15  in this embodiment, and the others remain unchanged. 
       FIG. 6  shows the sixth embodiment of the cable of the present invention. Compared with the fifth embodiment, the ground wire  18  is not provided in this embodiment, and the others remain unchanged. 
       FIG. 7  shows the seventh embodiment of the cable of the present invention. Compared with the fifth embodiment, the insulating layer  12  is integrally formed and extruded on the two inner conductors  11 , and the others remain unchanged. 
       FIG. 8  shows the eighth embodiment of the cable of the present invention. Compared with the seventh embodiment, the ground wire  18  is not provided in this embodiment, and the others remain unchanged. 
     The above describes only some of the embodiments of the present invention, but not all of the embodiments. Any equivalent changes to the technical solutions of the present invention by those skilled in the art by reading the description of the present invention are covered by the claims of the present invention.