Abstract:
A network interface system or device is disclosed that represents an optimal balance in the cost of the materials for the components and the cost of the assembly time required of a field technician. One or more lines from the network provider, e.g., a telephone company, are provided as well as one or more corresponding lines from a customer. For a given network line and corresponding customer line, each line is preferably terminated with a female spade connector. A small printed circuit board (PCB) is provided that has ends shaped to act as male spade connectors. An electrical connection is provided between the ends of the PCB. Optionally, but preferably, a gas tube is provided to suppress surges on the network line before they damage equipment connected to the customer line. A PCB configured in this manner can connect one set or multiple sets of lines.

Description:
This application is a continuation-in-part of application Ser. No. 08/939,747, filed on Sep. 27, 1997, entitled “Network Interface Device With Circuit Board Architecture,” now U.S. Pat. No. 6,322,375, the entire contents of which are hereby incorporated by reference. 
    
    
     FIELD OF THE INVENTION 
     The invention is generally directed toward the field of wire-to-wire connectors, and more particularly, to the field of network interface devices, and even more particularly, to the field of network interface devices between telephone company signal lines and customer signal lines. 
     BACKGROUND OF THE INVENTION 
     A customer subscribing to networked services, e.g., from a telephone company, typically owns a portion of the equipment over which the signals are transmitted. It has become a requirement that a point of demarcation be set between the equipment owned by the network provider, e.g., a telephone company, and the equipment owned by the customer. Typically, this point of demarcation takes the form of a network interface device (NID) located immediately outside the customer&#39;s building. 
     At the NID, signal lines from the networked provider are connected to signal lines from the customer. An example of a simple background art NID is a surge suppressor, typically in the form of a gas tube, that is encapsulated in plastic and provided with binding posts or screw terminals by which connections to the customer&#39;s line, the telephone company&#39;s, or network line and a ground connection are made. 
     Another type of network interface device (NID) is the subject of U.S. Pat. No. 6,322,375 by some of the Inventors of the present application. There, a device is disclosed that uses a printed circuit board (PCB) with multiple connector types. The network lines and the customer lines are preferably connected to the PCB by way of insulation displacement connectors (IDCs) that are located at points on the interior of the board. In an IDC, the wire is inserted between two blades that cut through the insulation and grip the wire with a strong force. Some IDCs provide a gas-tight connection. 
     The multiple connector types on the PCB of the U.S. Pat. No. 6,322,375 permit a service technician to easily perform a variety of diagnostic tests. The provision of the IDCs permits the network line and the customer line to be connected very quickly to the PCB. 
     The speed at which connections can be made to the NID of the copending application is a great advantage. In the telecommunications market, it is extremely important to provide equipment that minimizes the time spent by a technician in the field. The IDCs save a great deal of time because they free the service technician from having to strip insulation from the ends of the network line and the customer line, (possibly) attach a connector to those lines, and then mechanically couple the lines to corresponding connectors on the NID. Unfortunately, the cost of the IDCs is very significant, which commensurately raises the cost of the NID. 
     SUMMARY OF THE INVENTION 
     An advantage of the invention is that it provides a very inexpensive, and relatively quick to assemble in the field, network interface connection technology. 
     The invention, in part, represents a recognition that a simplified network interface device (NID), that requires more manual installation steps than, e.g., the IDCs of the NID according to the copending application, can achieve significantly reduced overall costs. 
     The invention, in part, provides a network interface system comprising: a network signal line and a printed circuit board (PCB). Such a PCB has at least a first connector and a second connector by which an electrical and mechanical connection is made to said network signal line and another signal line, e.g., a user or customer signal line. Such a printed circuit board also provides an electrical connection between said first connector device and said second connector device. 
     The invention also provides, in part, a printed circuit board (PCB) in a network interface system. Such a printed circuit board comprises: a non-conductive substrate; wherein said printed circuit board includes at least a first projection and a second projection configured to dimensions of a male spade connector; and at least a first conductive layer extending from said first projection and a second conductive layer extending from said second projection such that female spade connectors mechanically connected to said first projection and said second projection are also electrically connected to said first and second conductive layers. 
     Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only (it is noted that the drawings are not drawn to scale), and thus are not limitative of the present invention, and wherein: 
     FIG. 1A depicts an exploded view of a first embodiment of the network interface system according to the invention; 
     FIG. 1B depicts an optional weather-resistant enclosure around the embodiment of FIG. 1A; 
     FIG. 1C depicts a cross section along the line I-I′ of FIG. 1A; 
     FIG. 2A depicts a second embodiment of the network interface system according to the invention; 
     FIG. 2B depicts a cross section of the printed circuit board (PCB) of FIG. 2A taken along the view line II-II′; 
     FIG. 3A depicts a third embodiment of the network interface system according to the invention; 
     FIG. 3B depicts a side view of the embodiment of FIG. 3A taken along the view line III-III′; 
     FIG. 4 depicts a printed circuit board (PCB) of a fourth embodiment of the network interface system according to the invention; 
     FIG. 5 depicts a fifth embodiment of a printed circuit board (PCB) of a fifth embodiment of the network interface system according to the invention; 
     FIG. 6 depicts a printed circuit board (PCB) of a sixth embodiment of the network interface system according to the invention; and 
     FIGS. 7A,  7 B,  7 C,  8 A,  8 B,  8 C,  9  and  10  depict views of seventh, eighth and ninth embodiments of the network system according to the invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1A is an exploded view of a first embodiment  100  of a network interface system or device according to the invention. The network interface device (NID)  100  includes a printed circuit board (PCB)  101  and connectors or terminals  106 . One of the terminals  106  is connected to a wire  110  from the network provider, e.g., the telephone company. The other terminal  106  is connected to another wire  114 , e.g., from a customer. 
     The connectors  106  are preferably low in cost and of a design that requires relatively little manual assembly to attach to the respective wires  110  and  114 . A preferred embodiment of the terminals  106 , as depicted in FIG. 1A, is the female configuration of the well-known spade terminal. The spade terminals  106  are mechanically and electrically attached to the wires  110  and  114  via a crimp  108 . 
     A conductive layer or wire run  102  is formed on the surface of the PCB  101  and establishes an electrical connection between opposite ends  111  and  115  of the PCB  101 . This aspect is more easily observed in the cross-sectional view of FIG. 1C, which corresponds to the view line I-I′ of FIG.  1 A. 
     The PCB  101  is preferably small. But it is sufficient in size to accommodate the optional, but preferred, surge suppressor  104 . The surge suppressor  104  in FIG. 1A takes the form of the well-known gas tube. An alternative to the gas tube surge suppressor would be a solid state over-voltage and/or over-current protector device. One lead of the gas tube  104  is connected to the wire run  102  while the other lead is connected to ground. 
     The widths and thickness of the ends  111  and  115  of the PCB  101  have been selected so that they act as the male counterparts to the female spade connectors  106 . The NID  100  is assembled by attaching the connectors  106  to the wires  110  and  114 , and then pushing the female spade connectors  106  onto the male ends  111  and  115  of the PCB  101 . 
     FIG. 1B depicts a non-exploded view of the NID  100  of FIG. 1A with the addition of a weather resistant and/or electrically insulating covering  118  that encloses the NID  100 . A preferred embodiment of the covering  118  is heat shrink tubing that can be applied to the NID  100  and shrunk to fit by a field technician after assembly of the NID  100 . 
     In environments that promote corrosion of metal components, a weather resistant covering  118  has the advantage of retarding corrosion, which extends the usable lifetime of the NID  100 . Some harsh weather environments include installations near the coast, especially near salt water, as well as installations that are intended to be submerged or that face the intermittent problem of submersion due to flooding. 
     Also, the covering  118  can be selected to act as a dielectric that can insulate the NID  100  from adjacent network interface devices. This has the advantage of preventing a short-circuit between adjacent NID&#39;s that might occur by incidental contact of otherwise uninsulated metal connections. 
     FIG. 2A is an exploded schematic view of a second embodiment of the network interface system or device according to the invention. Differences relative to FIG. 1A will be emphasized. In FIG. 2A, a conductive layer  204  covers an entire surface of the PCB  202 . Unlike the PCB  101  of FIG. 1A, the PCB  202  is not provided with a surge suppressor device. Some regions are not required by the government to have a surge suppressor incorporated into the NID. 
     Also in FIG. 2A, two lines  110 A and  110 B from the network provider are depicted as well as two lines  114 A and  114 B from the customer. The lines  110 A and  114 A together represent the tip wire, while the lines  110 B and  114 B together represent the ring wire. Typically, the provision of telephone service requires the use of a tip wire and a ring wire to establish a single telephone line. 
     A network interface device (NID) enclosure  200  is depicted as a housing for the tip NID and the ring NID. The weather resistant and/or dielectric cover  118  of FIG. 1B is an undepicted option for each of the tip NID and the ring NID of FIG.  2 A. 
     FIG. 3A is an exploded, schematic depiction of a third embodiment of the network interface system or device according to the invention. Differences relative to FIGS. 1A and 2A will be emphasized. Rather than the separate PCB&#39;s  202  of FIG. 2A, FIG. 3A depicts a single PCB  302  that is used to connect the tip wires  110 A and  114 A as well as the ring wires  110 B and  114 B. 
     The PCB  302  has a shape resembling the letter “H.” This results from having provided ends  111 A,  111 B,  115 A, and  115 B that are dimensioned so as to define a male counterpart to the female spade terminals  106 . Two wire runs  304  and  306  are formed on the surface of the PCB  302 . The wire run  304  provides an electrical connection between the ends  111 B and  115 B, while the wire run  306  provides and electrical connection between the ends  111 A and  115 A. Because the PCB  324  makes a connection in two lines (here, a tip line and a ring line), it can be regarded as defining a wire pair unit. 
     The PCB  302  preferably, but not necessarily, includes a surge suppressor device in the form of a well-known three-terminal gas tube. One terminal of the gas tube is connected to the wire run  304 , while the second terminal is connected to the wire run  306 . The third terminal is connected to a ground stud  310 , which is itself connected to ground, or another wire run (not depicted) that is connected to ground. 
     FIG. 3B is a cross-sectional view of the third embodiment of FIG. 3A taken along the view line III-III′. It is noted that the weather resistant and/or dielectric covering  118  is an undepicted option that can be added to the NID  301  within the NID enclosure  300  of FIG.  3 A. 
     FIG. 4 depicts a fourth embodiment of a printed circuit board (PCB)  400  that forms the basis of a fourth embodiment of the network interface system or device according to the invention. The PCB  400  has a dielectric substrate  402 . Four wire runs  404  that correspond to two pairs of tip and ring lines are formed on the substrate  402 . The PCB  400  can be regarded as having two wire pair units. 
     Each pair of tip and ring wire runs  404  is connected to a surge suppressor device  308  in FIG.  4 . The surge suppressor devices are commonly connected to a ground line. 
     Any number of lines can be accommodated on the PCB that forms the basis of a network interface system or device according to the invention. When the network is a telephone network, as mentioned previously, the minimum number of wires is typically two. Also, additional wires are typically provided in multiples of two. 
     As noted previously, FIG. 4 depicts the PCB  400  as having two wire pair units. Similarly, FIG. 5 depicts five wire pair units on the PCB  500  having a dielectric substrate  502  and ten wire runs  404 . One pair of lines A is illustrated. Five pairs of lines are typically provided in Brazil, for example. FIG. 6 depicts a six wire pair units on the PCB  600  having a dielectric substrate  602  that includes twelve wire runs  404 . Six pairs of lines are commonly provided in the U.S.A., for example. 
     The connectors or terminals  106  have been described as preferably being female spade connectors. This is preferred because the PCB according to the invention can be configured to act as the corresponding male counterpart without the need to attach separate male counterpart connectors to the PCB. But other connectors can be chosen. Instead of spade connectors  106 , banana pin connectors can be employed, e.g., as depicted in FIG. 10. A male counterpart banana plug would be fitted to the wires while a corresponding solder plate hole, or socket, or receptacle would be provided on the PCB. Or, the PCB could be configured as a cylinder so as to define a male banana plug component and the wires could be terminated in female banana plug counterparts. 
     Further alternatives are to forego the use of connectors or terminals  106  and instead use screw terminals (as in FIGS. 7A,  7 B and  7 C), or binding posts (as in FIGS. 8A,  8 B and  8 C), or spring-loaded connection units (as in FIG. 9) mounted on the PCB. Bare ends of the wires from the customer and the network are inserted into the spring-loaded connection units. 
     Yet, another alternative (not depicted) is to use a combination of a female spade terminal and an insulation displacement connector (IDC). The female spade portion of this alternative would be used to connect to the ends of the PCB in the same manner as, for example, the terminals  106  of FIGS. 1A and 2A. The IDC portion of this alternative would be used to more quickly be able to connect to the wires from the customer and the network provider to the spade terminals. The IDC portions would replace the need to manually crimp the spade connector to the wire, but would increase cost. 
     As an alternative to the heat shrink tubing, weather resistant tape or a weather resistant curing polymer gel could be used. The material selected for the weather resistant and/or dielectric cover  118  will represent a balance of the competing factors of cost, assembly time for the field technician, weather resistance and/or resistivity. 
     The network interface system or device to the invention can also be provided with filters, and/or test access ports such as an RG- 11  connector. 
     The PCBs  302 ,  400 ,  500  and  600  have been depicted as having wire runs that connect corresponding male-spade-connector-configured ends together. An alternative is to not connect all of these ends together. Rather, at least some of these ends can have a wire run that leads to a component on the board. 
     An advantage of the network interface system or device according to the invention is that a customer can initially be provided with the simple PCB  202  of FIG.  2 A and later easily upgrade to a surge suppressing PCB such as PCB  101  of FIG.  1 A. Or, as additional lines are provided from the network provider, the PCB  102  or PCB  202  or PCB  302  could be replaced by the PCBs  400 ,  500 , or  600 . 
     Again, an advantage of the network interface system or device according to the invention is that it is low in cost, both in terms of the components as well as the cost represented by the time consumed by a field technician while assembling these devices. 
     Another advantage of the network interface system or device according to the invention is that the lines from the customer and the network are physically separated at their point of connection either by the covering or by the spacing inherent to the PCBs  302 ,  400 ,  500  or  600 . This lessons the problem of cross-talk. 
     Another advantage of the network interface system or device according to the invention is that a variety of different gauges of wire can be easily connected to the same network interface device using the same types of connectors or terminals, e.g.,  106 . This confers the further advantage of an economy of scale. 
     The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.