Patent Publication Number: US-11029368-B2

Title: Test point adaptor for coaxial cable connections

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation of U.S. application Ser. No. 15/408,355, filed Jan. 17, 2017, which is a nonprovisional application claims the benefit of U.S. Provisional Application No. 62/279,613, filed on Jan. 15, 2016. The disclosure of the prior applications is hereby incorporated by reference herein in its entirety. 
    
    
     BACKGROUND 
     Test adaptors or test point adaptors are used in order to test the properties of communication networks such as cable TV and computer networks using, for example, coaxial cables. In order to carry out a test, it is necessary to provide access points in which test equipment may be connected. 
     Testing of coaxial cables has become increasingly important due to the fact that increasingly more digital signals are carried in the cable. Disturbance in the signal, i.e. the signal/noise ratio, of digital signals is more likely to occur than when only analog signals were use. Thus, ensuring a high quality of the cables including connectors has become increasingly critical. Furthermore, the end user of a connection is increasingly more dependent on the reliability of their connection (e.g., by using IP-telephony, VPN, and similar products) and does not accept line dropout, for example, when their connection is being tested. For example, Internet Service Providers demand increased testing of the lines in order to ensure that they will be able to supply their service with a desired quality of service and without dropouts. 
     Typically, when inserting test equipment, the coaxial cable is disconnected from, for example, an amplifier or similar equipment that the coaxial cable is connected to. Various components are assembled to achieve an adaptor having an access point for testing, with the adaptor being inserted between the coaxial cable and, for example, an amplifier. In this way, the adaptor provides for testing during use of the cable. One example of such a test point adaptor is described in PCT International Publication Number WO 2011/079196, which is incorporated herein by reference. 
     In some applications, a test point adaptor may provide an interface for use with test equipment that requires a sliding connection with a port of the test point adaptor, as opposed to a convention threaded connection (e.g., an F-type connection), a bayonet connection, or the like. Similarly, a terminator cap would be slidably connected to the test point adaptor to short the RF signal to the outer conductor. Some conventional sliding connection can be less reliable than threaded connections with respect to preventing escape of the RF signal. 
     It may thus be desirable to provide a test point adaptor that provides a sliding connection with improved electrical continuity relative to the RF signal. It may be desirable to provide a sliding connection that provides a watertight seal while avoiding possible structural damage to the connection when slidably mating a terminator cap with the test point adaptor. 
     SUMMARY 
     According to some aspects of the disclosure, a test point adaptor for coaxial cables includes a main body, a test body, and a cap. The main body has a first longitudinal axis and includes a first end comprising a first interface, a second end comprising a second interface, and a first center conductor extending at least from the first interface to the second interface. The test body has a second longitudinal axis arranged transversely to the main body and includes an outer conductive sleeve, a test body end comprising a third interface, an electrically conductive contact member in electrical contact with the first center conductor, and a gripping arrangement electrically coupled with the electrically conductive contact member. The third interface includes a conical contact surface of the outer conductive sleeve. The cap includes a sleeve configured to matingly engage an outer surface of the outer conductive sleeve. The outer conductive sleeve includes a conical contact surface configured to engage the conical contact surface of the outer conductive sleeve when the cap is matingly engaged with the outer sleeve. The cap includes a terminator configured to be aligned with and received by the gripping arrangement, which electrically couples the terminator to the electrically conductive contact member. 
     In accordance with various aspects of the disclosure, a test point adaptor for coaxial cables includes a main body, a test body, a cap, and a sealing member. The main body has a first longitudinal axis and includes a first end comprising a first interface, a second end comprising a second interface, and a first center conductor extending at least from the first interface to the second interface. The test body has a second longitudinal axis arranged transversely to the main body and includes an outer conductive sleeve, a test body end comprising a third interface, an electrically conductive contact member in electrical contact with the first center conductor, and a gripping arrangement electrically coupled with the electrically conductive contact member. The cap includes a sleeve configured to matingly engage an outer surface of the outer conductive sleeve. The cap includes a terminator configured to be aligned with and received by the gripping arrangement, which electrically couples the terminator to the electrically conductive contact member. The cap includes an inner surface having an annular groove configured to receive the sealing member. The sealing member is configured to engage an outer surface of the outer conductive sleeve when the cap is matingly engaged with the outer surface of the outer conductive sleeve to provide a watertight connection at the third interface. An endmost region of the outer surface of the outer conductive sleeve has an outside diameter that is smaller than a region of the outer conductive surface that engages the sleeve of the cap. When the cap is coupled with the outer conductive sleeve, the sealing member is configured to engage the outer surface of the outer conductive sleeve to achieve the watertight connection, while the sleeve of the cap does not matingly engage the endmost region of the outer conductive sleeve. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention is to be described in detail with reference to the accompanying drawings, in which: 
         FIG. 1  is a perspective view of an exemplary test point adaptor according to various aspects of the disclosure, 
         FIG. 2  is a cross sectional view of the exemplary test point adaptor of  FIG. 1 , 
         FIG. 3  is an enlarged cross-sectional view of a second end of the test body and cap of the exemplary test point adaptor of  FIG. 1 , and 
         FIG. 4  is a perspective view of the cross-section of the second end of the test body of the exemplary test point adaptor shown in  FIG. 3  with the cap removed. 
         FIG. 5  is an enlarged cross-sectional view of an alternative second end of the test body and cap of  FIG. 3 . 
         FIG. 6  is an enlarged cross-sectional view of another alternative second end of the test body and cap of  FIG. 3 . 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
       FIG. 1  illustrates an exemplary test point adaptor  1  having a main body  2  and a test body  11  coupled with one another. The main body includes a first end  3  comprising a first interface  4 , for example, a swivel member or swivel nut, and a second end  5  comprising a second interface  6 . A first center conductor  7  is arranged in the main body  2  extending beyond the first end  3 . The test body  11  has a first test body end  13  connected with the main body  2 , for example, via a screw connection, and a second test body end  14  comprising a third interface  15 . In the illustrated embodiment of the test point adaptor  1 , the first interface  4  is a male threaded interface and the second interface  6  is a female threaded interface. However, it should be appreciated that in some embodiments, both of the first and second interfaces  4 ,  6  may be female threads, both may be male threads, or they may be other kinds of engaging means. 
     Referring now to  FIG. 2 , the first center conductor  7  is arranged along a longitudinal axis  8  of the main body  2 . The first center conductor  7  is kept substantially in the center of the main body  2  by a first seizure  9  and a second seizure  10 . The test body  11  is coupled with the main body  2  such that a longitudinal axis  12  of the text body  11  is substantially perpendicular to the longitudinal axis  8  of the main body  2 . It should be appreciated that the test body  11  may be coupled with the main body  2  in other ways than substantially perpendicular to the main body  2 , for example, at an angle such as 15°-90°, such as 25°-80°, such as 35°-70°, or such as 35°-55°. 
     As mentioned above, the first test body end  13  of the test body  11  may be threadably coupled with the main body  2 . A seizure  16  is mounted at the first test body end  13 . The seizure  16  is provided with an annular projection  17 . A spring  19  is arranged between the annular projection  17  of the seizure  16  and an end rim  18  of the first test body end  13 . The seizure  16  is arranged so as to be able to move along the longitudinal axis  12  of the test body  11 . The spring  19 , for example, an annular spring washer, biases the seizure  16  along the longitudinal axis  12  of the test body  11  in the direction away from the second end  14  of the test body  11 . 
     A contact member  20  is inserted in a central seizure aperture  21  of the seizure  16 . The contact member  20  is provided with a central aperture  22  for receiving a first end  24  of a resistor  23  or similar. Having positioned the first resistor end  24  in the central aperture  21  of the seizure  16 , the central aperture  22  of the contact member  20  is arranged to receive the first resistor end  24 . When the contact member  20  is inserted in the central aperture  21  of the seizure  16 , the contact member  20  clamps around the first resistor end  24 . Thus, the first resistor end  24  is kept in position and the contact member  20  is fixed in the central aperture of the seizure  16 . As the contact member  20  is electrically conductive, the resistor  23  is in electrical contact with objects being in contact with the contact member  20 . 
     The resistor  23  extends internally in the test body  11  along the longitudinal axis  12 . At the second end  14  of the test body  11 , the resistor  23  is kept in position by a gripping arrangement  25 . The gripping arrangement  25  is provided with a central aperture  26 . The central aperture  26  of the gripping arrangement  25  is arranged so as to receive a second end  27  of the resistor  23 . The gripping arrangement  25  is electrically conductive so as to facilitate that the center pin of test equipment (not shown) may be inserted into the test body  11  in electrical contact with the resistor  23 . 
     The second end  14  of the test body  11  is terminated by a removable cap  28  comprising a terminator  29 , for example, a resistor, between a signal and ground. The terminator  29  is configured to provide electrical termination of a signal to prevent an RF signal from being reflected back from the second end  14  of the test body  11 , causing interference. The cap  28  is slidably coupled with the third interface  15  of the second end  14  of the test body  11 . Further, in order to achieve watertight connections, the test point adaptor  1  is provided with sealing members  31 ,  32 ,  33 , for example, O-rings. 
     Referring now to  FIGS. 3 and 4 , the test body  11  includes an outer conductive sleeve  40  having a conical contact surface  41  at the third interface  15 . The third interface  15  also includes a nonconductive sleeve  42 , for example, a plastic sleeve, concentrically coupled with the outer conductive sleeve  40  and surrounds the gripping arrangement  25  within the test body  11 . The nonconductive sleeve  42  is mechanically coupled with the outer sleeve  40  such that the sleeves  40 ,  42  are not axially slidable relative to one another. The nonconductive sleeve  42  includes a tapered opening  43  configured to assist with insertion of a lead  30  of the terminator  29  into the central aperture  26  of the gripping arrangement  25 . It should be understood that the gripping arrangement  25  may comprise a slotted sleeve, prongs, or any other gripping member that is capable of maintaining a forcible connection so as to ensure electrical continuity between the resistor  23  and either the terminator  29  or test equipment (not shown). 
     As best illustrated in  FIG. 4 , the cap  28  includes a sleeve  45  configured to matingly engage an outer surface  46  of the outer conductive sleeve  40 . The sleeve  45  of the cap  28  includes slots  46  extending in the direction of the longitudinal axis  12 . As a result of the slots  46 , the cap sleeve  45  can be manufactured with an inside diameter that is slightly smaller than the outside diameter of the outer sleeve  40 . Thus, when the cap sleeve  45  is slidably coupled with the outer sleeve  40 , the cap sleeve  45  is expanded to receive the outer sleeve  40 , and the cap sleeve  45  provides a biasing force against the outer sleeve  40  to provide electrical continuity between the cap  28  and the outer conductive sleeve  40 . 
     The cap  28  also includes an annular groove  50  in an inner surface of the cap sleeve  45 . The annular groove  50  is configured to receive a sealing member  51 , for example, an O-ring. The sealing member  51  is configured to engage the outer surface  46  of the outer conductive sleeve  40  when the cap  28  is matingly engaged with the outer surface  46  of the outer sleeve  40  to ensure a watertight connection at the third interface  15 . As shown in  FIGS. 3 and 4 , an endmost region  47  of the outer surface  46  of the outer sleeve  40  may have an outside diameter that is smaller than a region  48  of the outer surface  46  that engages the cap sleeve  45 . As a result, when the cap  28  is coupled with the outer sleeve  40 , the sealing member  51  may be configured to engage the outer surface  46  to achieve the watertight connection, while the cap sleeve  45  will not matingly engage the endmost region  47  to avoid possible damage to and/or deterioration of the connection. 
     The cap  28  also includes a conical contact surface  49  configured to engage with the conical contact surface  41  of the outer conductive sleeve  40  when the cap  28  is matingly engaged with the outer sleeve  40 . The conical contact surfaces  41 ,  49  provide a longer engagement interface between the cap  28  and the outer sleeve  40  than conventional caps that provide radial (i.e., non-conical) contact surfaces. Thus, the RF signal is less likely to escape at the third interface, despite only providing a sliding connection between the cap  28  and the outer sleeve  40  (i.e., instead of a threaded connection). Although  FIGS. 3 and 4  illustrate the conical contact surface  40  tapering radially inward and the conical contact surface  49  tapering radially outward, it should be understood that in some embodiments, the conical contact surface  40  may taper radially outward and the conical contact surface  49  may taper radially inward. 
     The described embodiment of the test body  11  and its components provide electrical contact between a test instrument (not shown) connected at the second end  14  of the test body  11 , which is in turn electrically connected with the contact member  20 . The contact member  20  is in contact with the first center conductor  8  arranged in the main body  2 . Further details of the seizure  16 , the contact member  20 , the spring  19 , and other features of the test point adaptor  1 , as well as mounting of the test point adaptor  1  on a component, are described in PCT International Publication Number WO 2011/079196, which is incorporated herein by reference. 
     Referring to  FIG. 5 , in some aspects of the test point adaptor  1 , the outer cap sleeve  45  may include an annular ridge  55  (or a series of intermittent ridges arranged annularly). The region  48  of the outer surface  46  of the outer conductive sleeve  40  that engages the cap sleeve  45  may include an annular groove  56  that is configured to matingly receive the annular ridge  55 . The annular ridge  55  and the annular groove  56  may be positioned on the cap sleeve  45  and outer sleeve  40 , respectively, to provide a positive connection force between the cap sleeve  45  and the outer sleeve  40 . As a result, the conical contact surfaces  41 ,  49  are urged against one another with a force when the cap sleeve  45  and the outer sleeve  40  are matingly connected to ensure electrical continuity. The annular ridge  55  and the annular groove  56  may provide tactile feedback to a user as to when the cap sleeve  45  and the outer sleeve  40  are matingly connected and may also help prevent the cap sleeve  45  and the outer sleeve  40  from sliding apart. 
     Referring now to  FIG. 6 , in some aspects of the test point adaptor  1 , the outer sleeve  40  may include a tapered outer surface. For example, the outer surface  40  may be tapered from point  66  toward a shoulder  67  of the outer sleeve  40 . That is, the outside diameter of the outer sleeve  45  may taper from point  66  to shoulder  67 . As discussed above, the cap sleeve  45  can be manufactured with an inside diameter that is slightly smaller than the outside diameter of the outer sleeve  40 . For example the cap sleeve may have an inside diameter that is slightly smaller than the outside diameter of the outer sleeve  40  at a point along the outer sleeve  40  that is between point  66  and shoulder  67 . Thus, when the cap sleeve  45  is slidably coupled with the outer sleeve  40 , the cap sleeve  45  is expanded to receive the outer sleeve  40 , and the cap sleeve  45  provides a biasing force against the tapered region of the outer sleeve  40  to provide electrical continuity between the cap  28  and the outer conductive sleeve  40 . As a result, the conical contact surfaces  41 ,  49  are urged against one another with a force when the cap sleeve  45  and the outer sleeve  40  are matingly connected to ensure electrical continuity. The tapered region of the outer sleeve  40  may cooperated with the cap sleeve  45  to help prevent the cap sleeve  45  and the outer sleeve  40  from sliding apart. 
     Additional embodiments include any one of the embodiments described above, where one or more of its components, functionalities or structures is interchanged with, replaced by or augmented by one or more of the components, functionalities or structures of a different embodiment described above. 
     It should be understood that various changes and modifications to the embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present disclosure and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims. 
     Although several embodiments of the disclosure have been disclosed in the foregoing specification, it is understood by those skilled in the art that many modifications and other embodiments of the disclosure will come to mind to which the disclosure pertains, having the benefit of the teaching presented in the foregoing description and associated drawings. It is thus understood that the disclosure is not limited to the specific embodiments disclosed herein above, and that many modifications and other embodiments are intended to be included within the scope of the appended claims. Moreover, although specific terms are employed herein, as well as in the claims which follow, they are used only in a generic and descriptive sense, and not for the purposes of limiting the present disclosure, nor the claims which follow.