Abstract:
A cable assembly ( 100 ) includes an insulative housing ( 2 ) defining a mounting cavity ( 221 ); an optical module ( 5 ) accommodated in the mounting cavity and capable of moving therein along a front-to-back direction; at least one fiber ( 6 ) coupled to the optical module; an elastomeric member ( 9 ) disposed in the mounting cavity and arranged behind the optical module; and a cap member ( 7 ) combined with the elastomeric member and fixed to the insulated housing.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This is a continuation-in-part (CIP) of U.S. patent application Ser. No. 12/647,412, filed on Dec. 25, 2009 and entitled “CABLE ASSEMBLY HAVING FLOATABLE OPTICAL MODULE”, which has the same applicant and assignee as the present invention. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a cable assembly, more particularly to a cable assembly capable of transmitting optical signal. 
         [0004]    2. Description of Related Art 
         [0005]    Recently, personal computers (PC) are used of a variety of techniques for providing input and output. Universal Serial Bus (USB) is a serial bus standard to the PC architecture with a focus on computer telephony interface, consumer and productivity applications. The design of USB is standardized by the USB Implementers Forum (USB-IF), an industry standard body incorporating leading companies from the computer and electronic industries. USB can connect peripherals such as mouse devices, keyboards, PDAs, gamepads and joysticks, scanners, digital cameras, printers, external storage, networking components, etc. For many devices such as scanners and digital cameras, USB has become the standard connection method. 
         [0006]    USB supports three data rates: 1) A Low Speed rate of up to 1.5 Mbit/s (187.5 KB/s) that is mostly used for Human Interface Devices (HID) such as keyboards, mice, and joysticks; 2) A Full Speed rate of up to 12 Mbit/s (1.5 MB/s). Full Speed was the fastest rate before the USB 2.0 specification and many devices fall back to Full Speed. Full Speed devices divide the USB bandwidth between them in a first-come first-served basis and it is not uncommon to run out of bandwidth with several isochronous devices. All USB Hubs support Full Speed; 3) A Hi-Speed rate of up to 480 Mbit/s (60 MB/s). Though Hi-Speed devices are advertised as “up to 480 Mbit/s”, not all USB 2.0 devices are Hi-Speed. Hi-Speed devices typically only operate at half of the full theoretical (60 MB/s) data throughput rate. Most Hi-Speed USB devices typically operate at much slower speeds, often about 3 MB/s overall, sometimes up to 10-20 MB/s. A data transmission rate at 20 MB/s is sufficient for some but not all applications. However, under a circumstance transmitting an audio or video file, which is always up to hundreds MB, even to 1 or 2 GB, currently transmission rate of USB is not sufficient. As a consequence, faster serial-bus interfaces are being introduced to address different requirements. PCI Express, at 2.5 GB/s, and SATA, at 1.5 GB/s and 3.0 GB/s, are two examples of High-Speed serial bus interfaces. 
         [0007]    From an electrical standpoint, the higher data transfer rates of the non-USB protocols discussed above are highly desirable for certain applications. However, these non-USB protocols are not used as broadly as USB protocols. Many portable devices are equipped with USB connectors other than these non-USB connectors. One important reason is that these non-USB connectors contain a greater number of signal pins than an existing USB connector and are physically larger as well. For example, while the PCI Express is useful for its higher possible data rates, a 26-pin connector and wider card-like form factor limit the use of Express Cards. For another example, SATA uses two connectors, one 7-pin connector for signals and another 15-pin connector for power. In essence, SATA is more useful for internal storage expansion than for external peripherals. 
         [0008]    The existing USB connectors have a small size but low transmission rate, while other non-USB connectors (PCI Express, SATA, et al) have a high transmission rate but large size. Neither of them is desirable to implement modern high-speed, miniaturized electronic devices and peripherals. To provide a connector with a small size and a high transmission rate for portability and high data transmitting efficiency is much more desirable. 
         [0009]    In recent years, more and more electronic devices are adopted for optical data transmission. It may be a good idea to design a connector which is capable of transmitting an electrical signal and an optical signal. Design concepts are already common for such a type of connector which is compatible of electrical and optical signal transmission. The connector includes metallic contacts assembled to an insulated housing and several optical lenses bundled together and mounted to the housing also. A kind of hybrid cable includes wires and optical fibers that are respectively attached to the metallic contacts and the optical lenses. 
         [0010]    However, optical lenses are unable to be floatable with regard to the housing. They are not accurately aligned with, and optically coupled to counterparts, if there are some errors in manufacturing process. 
       BRIEF SUMMARY OF THE INVENTION 
       [0011]    Accordingly, an object of the present invention is to provide a cable assembly has a floatable optical module. 
         [0012]    In order to achieve the above-mentioned object, a cable assembly in accordance with present invention comprises: an insulative housing defining a mounting cavity; an optical module accommodated in the mounting cavity and capable of moving therein along a front-to-back direction; at least one fiber coupled to the optical module; an elastomeric member disposed in the mounting cavity and arranged behind the optical module; and a cap member combined with the elastomeric member and fixed to the insulated housing. 
         [0013]    The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]    For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which: 
           [0015]      FIG. 1  is an assembled, perspective view of a cable assembly in accordance with the present invention; 
           [0016]      FIG. 2  is an exploded, perspective view of  FIG. 1 ; 
           [0017]      FIG. 3  is similar to  FIG. 2 , but viewed from another aspect; 
           [0018]      FIG. 4  is a partially assembled view of the cable assembly; 
           [0019]      FIG. 5  is a cross-section view of the cable assembly taken along line  5 - 5 ; and 
           [0020]      FIG. 6  is a cross-section view of the cable assembly taken along line  6 - 6 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0021]    In the following description, numerous specific details are set forth to provide a thorough understanding of the present invention. However, it will be obvious to those skilled in the art that the present invention may be practiced without such specific details. 
         [0022]    Reference will be made to the drawing figures to describe the present invention in detail, wherein depicted elements are not necessarily shown to scale and wherein like or similar elements are designated by same or similar reference numeral through the several views and same or similar terminology. 
         [0023]    Referring to  FIGS. 1-6 , a cable assembly  100  in accordance with the present invention is disclosed. The cable assembly  100  comprises an elongated insulative housing  2  extending along a front-to-back direction, a set of first contacts  3 , a set of second contacts  4  and an optical modules  5  supported by the insulative housing  2 , and a number of fibers  6  coupled to the optical module  5 . The cable assembly  1  further comprises a cap member  7 , a metal shell  8  and an elastomeric member  9 . The cap member  7  and the elastomeric member  9  are combined together. The elastomeric member  9  is capable of biasing the optical modular  5  along the front-to-back direction. Detail description of these elements and their relationship and other elements formed thereon will be detailed below. 
         [0024]    The insulative housing  2  includes a base portion  21  and a tongue portion  22  extending forwardly from the base portion  21 . A cavity  211  is recessed upwardly from a bottom surface (not numbered) of the base portion  21 . A mounting cavity  221  is recessed downwardly from a top surface of the tongue portion  22 . A stopping member  2212  is formed in a front portion of the mounting cavity  221 . A depression  224  is defined in a rear portion of the tongue portion  22  and communicating with the mounting cavity  221 . A number of contact slots  212  are defined in an upper segment of a rear portion of the base portion  21 . Two fiber grooves  213  are defined in the base portion  21  and extend along the front-to-back direction, pass the depression  224  and communicate with the mounting cavity  221 . 
         [0025]    The set of first contacts  3  have four contact members arranged in a row along the transversal direction. Each first contact  3  substantially includes a planar retention portion  32  supported by a bottom surface of the cavity  211 , a mating portion  34  raised upwardly and extending forwardly from the retention portion  32  and disposed in a depressed area  226  of the lower section of the front segment of the tongue portion  22 , and a tail portion  36  extending rearward from the retention portion  32  and accommodated in the terminal slots  212 . 
         [0026]    The set of second contacts  4  have five contact members arranged in a row along the transversal direction and combined with an insulator  20 . The set of second contacts  4  are separated into two pairs of signal contacts  40  for transmitting differential signals and a grounding contact  41  disposed between the two pair of signal contacts  40 . Each second contact  4  includes a planar retention portion  42  received in corresponding groove  202  in the insulator  20 , a curved mating portion  44  extending forward from the retention portion  42  and disposed beyond a front surface of the insulator  20 , and a tail portion  46  extending rearward from the retention portion  42  and disposed behind a back surface of the insulator  20 . A spacer  204  is assembled to the insulator  20 , with a number of ribs  2042  thereof inserted into the grooves  202  to position the second contacts  4  in the insulator  20 . 
         [0027]    The insulator  20  is mounted to the cavity  211  of the base portion  21  and press onto retention portions  32  of the first contacts  3 , with mating portions  44  of the second contacts  4  located behind the mating portions  34  of the first contacts  3  and above the up surface of the tongue portion  22 , the tail portions  46  of the second contacts  4  arranged on a bottom surface of the rear segment of the base portion  21  and disposed lower than the tail portions  36  of the first contacts  3 . 
         [0028]    The optical module  5  includes four lens members  51  arranged in juxtaposed manner and enclosed by a holder member  52  and accommodated in the mounting cavity  221 . 
         [0029]    Four fibers  6  are separated into two groups, passing the two fiber grooves  213  and entering a rear section of the mounting cavity  221 , and coupled to the four lens  51 , respectively. 
         [0030]    The elastomeric member  9  has an elongated body which is made of elastomeric material, such as rubber, elastic plastic and so on. The elastomeric member  9  is an elongated block, which can be rectangular shaped, cylindrical shaped, etc. There are two transversal cavities  91  defined in the elastomeric member  9 . The cavities  91  are spaced from each other along a transversal direction, and such design can increase flexibility of the elastomeric member  9 . In addition, the elastomeric member  9  and the cap member  7  have same thickness and are combined together by co-molding (two-shot molding) process. In alternative embodiment, the elastomeric member  9  is integrated to the cap member  7  by insert molding process. 
         [0031]    In assembling, the cap member  7  and the elastomeric  9  are simultaneously mounted to the insulative housing  2 . The cap member  7  is assembled to the depression  224  and the elastomeric member  9  is accommodated in the mounting cavity  221  along the transversal direction. The elastomeric member  9  abuts against a back edge of the holder member  52 , and two crushable ribs  71  are formed at the bottom surface of the cap member  7  and further inserted into positioning holes  2213  in the depression  224 , therefore the cap member  7  is fixed/secured to the insulative housing  2 . The fibers  6  are disposed underneath the cap member  7  and the elastomeric member  9 . The stopping member  2212  can prevent the optical module  5  sliding away from the mounting cavity  221 . 
         [0032]    The metal shell  8  comprises a first shield part  81  and a second shield part  82 . The first shield part  81  includes a front tube-shaped mating frame  811 , a rear U-shaped body section  812  connected to a bottom side and lateral sides of the mating frame  811 . The mating frame  811  further has two windows  8112  defined in a top side thereof. The second shield part  82  includes an inverted U-shaped body section  822 , and a cable holder member  823  attached to a top side of the body section  822 . 
         [0033]    The insulative housing  2  is assembled to the first shield part  81 , with the tongue portion  22  enclosed in the mating frame  811 , the cap member  7  arranged underneath the windows  8112 , and the base portion  21  is received in the body portion  812 . The second shield part  82  is assembled to the first shield part  81 , with body portions  822 ,  812  combined together. The cable assembly may have a hybrid cable which includes fibers  6  for transmitting optical signals and copper wires (not shown) for transmitting electrical signals. The copper wires are terminated to the first contacts  3  and the second contacts  4 . The cable holder member  823  is crimped onto the cable to enhance mechanical interconnection. 
         [0034]    It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed. For example, the tongue portion is extended in its length or is arranged on a reverse side thereof opposite to the supporting side with other contacts but still holding the contacts with an arrangement indicated by the broad general meaning of the terms in which the appended claims are expressed.