Patent Publication Number: US-11665842-B2

Title: Cable sealing assembly

Description:
TECHNICAL FIELD 
     The disclosure relates to a cable sealing assembly for a cabinet housing electronic equipment. 
     BACKGROUND 
     Electronic equipment like base station transceivers, servers and routers are normally mounted in cabinets. In outdoor installations it is important that the cable entry to the cabinet is securely sealed to prevent dust and humidity to enter the cabinet and damage the electronics. A cable entry for outdoor equipment is often designed to receive a plurality of cables. These can be of different sorts and sizes (copper, fibre), or having different purposes (power, transmission, signalling etc.). 
     U.S. Pat. No. 8,541,698 discloses an example of a cable distribution cabinet having a cable entry underneath the cabinet comprising a base plate for receiving and sealing a plurality of cables entering the cabinet. Within the base plate a plurality of elastic sealing blocks is threaded on guide rods resulting in two straight lines of holes for receiving cables. The cabinet in U.S. Pat. No. 8,541,698 is further configured with front doors allowing access to the cables and the electronics. 
     In compact installations where the cable entry is concentrated to a relatively small area underneath the cabinet, the cables need to be stacked in multiple rows or in bundles. This makes it difficult to access all cables during maintenance or upgrades of the cable configuration. Connecting or disconnecting the innermost cables in the stack for example, will be very difficult without interfering with or disconnecting other cables in front of the innermost cables. 
     Another problem is that with cable sealings having a plurality of through holes configured to receive a bundle of cables, it is difficult to apply an even pressure on the sealing for each individual cable. 
     SUMMARY 
     With this background it is the object of the embodiments described below to obviate at least one of these disadvantages. 
     The object is achieved by a cable sealing assembly having a tongue-shaped protruding member, an elastic cable sealing member and a corresponding recessed member configured to receive the protruding member and the cable sealing member in between. The elastic cable sealing member has a plurality of through holes forming a single row, each hole configured to have a cable extending there through and wherein the cable sealing member is configured to be shaped around the edge of the tongue-shaped protruding member. The cable sealing assembly is further configured to seal the cable entry when the protruding member and the recessed member together apply an even pressure on the cable sealing member. In one embodiment, the even pressure is achieved when the cabinet&#39;s detachable cover engages with the cable sealing assembly so that the protruding member and the recessed member applies the even pressure on the cable sealing member when the cover is mounted to the cabinet. 
     An advantage with the tongue-shaped assembly is that as the cables are mounted in a single row around the protruding member each individual cable can easily be accessed, inserted in or removed from the seal and plugged into or removed from the socket of the electronics without interfering with other cables. Another advantage is that when an even pressure is applied on the elastic cable sealing member it ensures that an even pressure is applied on each cable so that the cable entry becomes water and dust proof. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS.  1   a - 1   c    are block diagrams illustrating a cabinet having a cable entry and a cable sealing assembly according to any of the described embodiments. 
         FIG.  2    is a block diagram illustrating a first embodiment of a cable sealing assembly and its members. 
         FIG.  3    is a block diagram illustrating a second embodiment of a cable sealing assembly and its members. 
         FIG.  4    is a block diagram illustrating a third embodiment of a cable sealing assembly and its members. 
         FIG.  5    is a more detailed block diagram illustrating an embodiment of a cable sealing assembly when mounted in a cabinet. 
     
    
    
     DETAILED DESCRIPTION 
       FIGS.  1   a - 1   c    illustrate an outdoor installation of a cabinet  100  having a cable sealing assembly  200  as in any of the described embodiments.  FIG.  1   a    is a cross-section of a side view,  FIG.  1   b    is a cross-section of a front view and  FIG.  1   c    is a cross-section of a top and/or bottom view of said cabinet  100 . 
       FIG.  1   c    also illustrates a compact installation comprising a plurality  100 ,  101 ,  102  of such cabinets  100 . The cabinets  100 ,  101 ,  102  are all mounted side by side on a rail  190  which for example can be located on a wall. One short side of the cabinet  100  faces the rail  190 , the other short side is the front  140 . 
     The cabinet  100  comprises a metal enclosure  110  configured to house electronic and/or photonic equipment (such as digital baseband units, radio transceivers etc.) comprising one or several printed circuit boards (PCBs)  150 . The PCB(s)  150  comprise sockets  151  for plugging the cables  130  entering the cabinet  100  to the electronics. Each socket  151  faces the front  140  of the cabinet  100  and the cables  130  enter the cabinet  100  through a cable entry  115  underneath and at the front  140 . The cables  130  can be of different sorts (copper and/or fibre) and diameters. For maintenance or upgrades of the cable configuration, the front  140  is provided with a metal detachable cover  120 . To meet outdoor installation requirements, the cable entry  115  is further provided with a cable sealing assembly  200 . 
       FIG.  2    illustrates a first embodiment of a cable sealing assembly  200  comprising a tongue-shaped protruding member  210 , an elastic cable sealing member  220  and a corresponding recessed member  230  configured to receive the protruding member  210  and the cable sealing member  220  in between. The cable sealing member  220  is made of a silicon based material or a thermo plastic material preferably within the flexibility range of A30-A50 on the Shore hardness scale. The sealing member  220  has further a plurality of through holes  221 ,  222  (that could have different diameters) that forms a single row, each hole configured to have a cable  130  extending there through. Each hole  221 ,  222  is further configured with a slit  241 ,  242  extending from the hole  221 ,  222  to the exterior of the sealing member  220  and facing the recessed member  230  as to permit the insertion of a cable  130  when pulled apart. In this embodiment, the cable sealing member  220  is moulded in one piece having a V- or U-shape and configured to be shaped around the edge of the tongue-shaped protruding member  210 . To seal the cable entry  115  when the cables  130  are mounted, the protruding member  210  and the recessed member  230  are configured to together apply an even pressure  290  on the cable sealing member  220 . 
     In a second embodiment as illustrated by  FIG.  3   , the cable sealing member  220  comprises a plurality of sealing elements  311 - 315  which put together forms the sealing member  220 . Each element  311 - 315  is configured with at least one hole  3141  with a slit  3142  facing the recessed member  230 . Again, to seal the cable entry  115 , the protruding member  210  and the recessed member  230  are configured to together apply an even pressure  290  on the sealing elements  311 - 315 . 
     In a third embodiment illustrated by  FIG.  4   , the cable sealing member  220  comprises a first  421  and a second  422  v- or u-shaped sealing element each sealing element  421 ,  422  moulded in one piece and having a plurality of semi-circular cavities  425  in a row. When the two sealing elements  421 ,  422  are put together with the cavities  425  face to face, they form the sealing member  220  with through holes  430 , each hole  430  configured to have a cable  130  extending there through. 
     In the third embodiment both sealing elements  421 ,  422  can be loose elements but preferably the first sealing element  421  is attached to the protruding member  210  and the second sealing element  422  is attached to the recessed member  230 . 
       FIGS.  1   a - 1   c    and  FIG.  5    illustrate the cable sealing assembly  200  when mounted in the cable entry  115  of the cabinet  100 .  FIG.  5    shows a closer view illustrating that when the detachable cover  120  is mounted to the enclosure  110 , it engages with the cable sealing assembly  200  so that an even pressure  290  is applied on the sealing member  220 . 
     For the different embodiments of the cable sealing assembly  200  it is preferred that the protruding member  210  and the recessed member  230  are of metal and fixed to or being an integral part of the enclosure  110  and the detachable cover  120  respectively. 
     The cable sealing member  220  on the other hand is preferred to be easily replaceable. The sealing member  220  could optionally be kept in place on the protruding member  210  or the recessed member  230  by gluing or some other fastening means as long as it is easy to remove and attach. 
     Optionally, the cable sealing member  220  is at least partly covered with a conductive layer configured to provide a low impedance path between the protruding member  210  and the recessed member  230  when the cable entry  115  is sealed. The purpose of the conductive layer is to improve the electrical shielding performance, to be able to comply to relevant Electromagnetic Compatibility (EMC) requirements. When the cabinet  100  is mounted in close vicinity of radio frequency (RF) equipment, the conductive layer is also used to improve the PIM (Passive Intermodulation) performance. 
     As the cables  130  are mounted in a single row in the tongue-shaped cable sealing assembly  200 , each individual cable  130  can easily be accessed and each cable can be inserted in or removed from the seal and plugged into or removed from the socket  151  on the PCB  150  without interfering with other cables. 
     The installation procedure when using the first or the second embodiment of the cable sealing assembly  200 , is to remove the detachable cover  120  exposing the cable sealing assembly  200 . The cables  130  are inserted in its respective slit  241 ,  242 ,  3141 ,  3142  in the sealing element  220 . Different type of cables could have different outer diameters, hence need to be placed in a certain position. Already at this stage, the cables are held in place by the sealing element  220  itself. When the detachable cover  120  is mounted to the enclosure  110  it engages with the cable sealing assembly  200  so that the protruding member  210  and the recessed member  230  together apply an even pressure  290  on the cable sealing member  220  resulting in that each slit  241 ,  242 ,  3141 ,  3142  closes and the cable sealing assembly  200  becomes water and dust tight. When the cable configuration need to be changed, the detachable cover  120  is removed again and all cables  130  are easily accessible. 
     When using the described cable assembly  200  in the cable entry  115  it has been tested and verified to comply with at least the rating IP65 according to the Ingress Protection standard IEC 60529.