Patent Publication Number: US-2005115733-A1

Title: Compression unit

Description:
TECHNICAL FIELD  
      The present invention concerns a frame for cable entries, pipe penetrations or the like. More specifically the invention concerns a compression unit to be used in said frame.  
     PRIOR ART  
      Different frames of this kind are widely used today. The frames are parts of systems used to seal at a cable entry, pipe penetration etc. In addition to the frame the systems normally comprises further elements to be placed tightly surrounding the cables etc. Systems of this kind are used in many different environments, such as for cabinets, technical shelters, junction boxes and machines. They are used in different industrial environments, such as automotive, telecom, power generation and distribution, as well as marine and offshore.  
      The seals may have to seal against fluid, gas, fire, rodents, termites, dust, moisture etc. The seal may receive cables for electricity, communication, computers etc. or pipes for different gases or liquids such as water, compressed air, hydraulic fluid and cooking gas.  
      In a common type of frames of this kind rather intricate compression units are used to put pressure on the separate units receiving cables, pipes etc. The pressure is needed to give a positive sealing. The compression units often comprise a number of different parts, including screws or the like used to displace two or more parts in relation to each other, which parts may have the form of wedges. These more complex compression units are needed, when e.g. the demands regarding maximal pressure difference on each side of a wall are relatively high. However, if the demands are not that severe such compression units may be felt as too complicated both regarding manufacture and handling. Thus, there is a need for a more simple, but yet reliable compression unit, which may be used when the demands are somewhat lower.  
     SUMMARY OF THE INVENTION  
      In view of the above, the compression unit of the present invention is mainly intended for frames having medium or lower demands on the sealing, regarding the pressure it can withstand.  
      One object of the present invention is to arrange a simplified but yet robust compression unit for a frame, which compression unit should be relatively easy to use. A further object is that the compression unit should have as few parts as possible, simplifying both the production and general handling of the compression unit. Furthermore, the compression unit should be possible to use with different frames. It is also an advantage if the compression unit has small or no risk of malfunction.  
      According to the present invention a compression unit for a frame, receiving one or more separate units for cable entries, pipe penetrations etc., is arranged. Said compression unit comprises a compression plate to be received turnable in the frame. The compression plate and frame are connected by means of protrusions and grooves.  
      Further objects and advantages of the present invention will be obvious for a person skilled in the art, when reading the detailed description below of one at present preferred embodiment of the present invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The invention will now be described further below, by way of an example and with reference to the drawings below. In the drawings:  
       FIG. 1  is a perspective view of a frame according to the present invention;  
       FIG. 2  is a perspective view of a part used for forming the frame of  FIG. 1 ;  
       FIG. 3  is a perspective view of a compression plate to be received in the frame of  FIG. 1 ;  
       FIG. 4  is a perspective view of a cover to be used with a compression plate of  FIG. 3 ;  
       FIG. 5  is a perspective view of the cover of  FIG. 4  taken from the opposite direction;  
       FIG. 6  illustrates in cross section a line of operations for mounting of a compression plate in the frame;  
       FIG. 7  is a front view indicating a frame according to the present invention in use;  
       FIG. 8  is a perspective view of an alternative compression plate according to the invention;  
       FIG. 9  is a part view of an alternative frame according to the present invention; and  
       FIG. 10  is a perspective view of an alternative compression plate according to the present invention. 
    
    
     DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT  
      The expressions “horizontal”, “vertical”, “upper”, “lower” and similar expressions, as used in this description, are with reference to the directions as shown in the enclosed Figs. A person skilled in the art realises that the frame may have any orientation in use.  
      The present invention is used in connection with frames  1  for receiving one or more separate units  2  in the form of cable entries, pipe penetrations etc. The frame  1  is used to bring cables, pipes etc. through an opening of a wall, ceiling etc. in a sealed way.  
      In the embodiment shown in the enclosed drawings, the frame  1  is formed of two frame parts  8 . Even tough the frame  1  is shown as made of two parts  8 , the invention is not limited to such frames. A person skilled in the art realises that it is of no importance for the invention as such if the frame  1  is made of only one single, two or more parts. As indicated in  FIGS. 6 and 7  the frame may have a flange for abutment against a wall or the like. The frame parts  8  of the shown embodiment are brought together and fixed to one side of the wall, ceiling or the like. The frame  1  is furnished with a number of through holes  11  for receiving suitable fastening means. In the shown embodiment bolts  12  are used as fastening means. A person skilled in the art realises that any fastening means giving a secure fixation of the frame  1  to the wall may be used. Thus, it is possible to use rivets, welding, soldering, glue etc. or a combination of different fastening means.  
      Inside the frame  1  a number of separate units  2  are received. Said separate units  2  have the form of cable entries, pipe penetrations etc. The separate units  2  are made of an elastic material, giving a sealing effect when put under pressure. Between different rows of separate units  2 , partitions  13   a,    13   b  are arranged. The partitions  13   a,    13   b  are arranged in such a way within the frame  1  that the partitions may slide in relation to the frame  1 . Furthermore, a compression plate  3  is received in the frame  1 . The uppermost partition  13   a,  i.e. the one in contact with the compression plate  3  is often made stronger than the rest of the partitions  13   b.  This is normally achieved in that said uppermost partition  13   a  is made thicker than the rest of the partitions  13   b.    
      The compression plate  3  has a generally rectangular form in the shown embodiment. On each short side of the compression plate  3  a protrusion  5  is arranged. Each protrusion  5  is formed with long and short sides aligned with the extension of the short sides of the compression plate  3 . The long sides of the compression plate  3  have bevels  7 . Furthermore, the compression plate has an opening  6 , which preferably is a through opening  6 . The compression plate  3  may be formed of any material plastic, metal etc. giving enough stiffness. The exact form of the compression plate  3  may vary but is adapted to the form of the frame  1 , which is to receive the compression plate  3 .  
      The protrusions  5  of the compression plate  3  are to co-operate with grooves  9 ,  10  of the frame  1 . The grooves of the frame  1  have a straight introduction part  9 , which goes over into a rounded part  10 . The grooves  9 ,  10 , as shown in the enclosed Figs., are not through grooves and, thus, are ended by the rounded part  10 . However, in alternative embodiments (not shown) the grooves may be through grooves, allowing insertion of a compression plate  3  from either side of the frame. For such through grooves the rounded part  10  is normally placed in the middle, with straight parts  9  on both sides. The dimensions of the protrusions  5  of the compression plate  3  and the grooves  9 ,  10  of the frame  1  are such that the compression plate  3  may be inserted into the frame  1  and then turned. Furthermore, the round parts  10  of the grooves have a locking function, i.e. when the compression plate  3  is in a vertical position it is hindered from going along the groove  9 ,  10 . The compression plate  3  is introduced into the frame  1  directed mainly perpendicular to the general extension of the frame  1 . The grooves  9 ,  10  are arranged at the upper part of the frame  1 . The grooves  9 ,  10  are positioned to enable for the compression plate  3  to be pressed against the upper vertical part of the frame  1 , when the compression plate  3  is turned in the frame  1 . In that the compression plate  3  abuts and is pressed against the upper part of the frame  1 , the compression plate  3  will transfer that pressure to the separate units  2  of the frame  1 , placed below said compression plate  3 .  
      In an alternative embodiment the grooves of the frame  1 ′ receiving the compression plate  3 ′ have a different form. For said grooves there is no connection between the straight part  9 ′ and the rounded part  10 ′ of the grooves. These types of grooves are intended for use with relatively flexible frames  1 ′. To mount the compression plate  3 ′ the protrusions  5 ′ of the plate is first introduced in the straight part  9 ′ of the grooves. To bring the protrusions  5 ′ into the rounded part  10 ′ of the grooves, the frame  1 ′ is flexed just enough to allow the protrusions  5 ′ to pass from the straight to the rounded parts  9 ′,  10 ′ of the grooves. With the protrusions  5 ′ in the rounded parts  10 ′ of the grooves the compression plate  3 ′ may be turned in the same way as described above. In a further alternative embodiment the grooves have no straight part, in which case the protrusions  5 ′ of the plate  3 ′ are brought directly into the rounded parts by flexing the frame. The protrusions  5 ′ of the compression plates  3 ′ often have a circular form when co-operating with grooves having separated straight and rounded parts.  
      A person skilled in the art realises that the exact form and position of the protrusions  5  and grooves  9 ,  10  may vary. The only demand is that it should be possible to introduce the compression plate  3  in the frame  1  and then to turn the compression plate  3  to a position in which it puts pressure on the separate units  2  in the frame  1 . As stated above the compression plate  3  should be locked in a vertical position by the protrusions  5  and grooves  9 ,  10 .  
      Furthermore, a cover  15  is arranged, which is to be placed over the compression plate  3 , in order to seal the area of the compression plate  3  in the frame  1 . The cover  15  has the same general rectangular form as the compression plate  3 . The side of the cover  15  intended to be faced outwards is slightly inclined and, thus, the short sides of the cover  15  have one narrow end  16  and one broad end  17 . At the broad end  17  of the cover  15  a notch  18  is formed, which notch  18  goes along the lower long side of the cover  15 . The notch  18  is to be placed along the uppermost partition  13   a.  On one side of the cover  15  a knurl  19  is provided, which is to be received in the opening  6  of the compression plate  3 . The cover  15  has also a protruding rim and protrusions  20 , which protrusions  20  are to be received in the straight parts  9  of the grooves. The notch  18 , the rim, the knurl  19  and the protrusions  20  of the cover  15  contribute to the fixation of said cover  15  to the frame  1 . The cover  15  is normally formed of rubber or other elastic material.  
      In an alternative embodiment, indicated in  FIG. 8 , the compression plate  4  also fulfils the function of the cover. The compression plate  4  according to the embodiment of  FIG. 8  has the same general form as the previously described compression plate  3 . Furthermore, it has protrusions  5 , an opening  6  for a tool, and bevelled sides  7 . The difference to the previously described compression plate  3  is that the compression plate  4  is furnished with sealings  21 ,  22 . One sealing  21  goes in the middle of all sides that are to be in contact with the frame  1  or parts  13   a  received in the frame when the compression plate  4  is in a vertical position. Furthermore, one sealing  22  is placed in a circle around each protrusion  5 . The sealings  21 ,  22  may be received in grooves in the compression plate  4 . However, it is also possible to fix the sealings  21 ,  22  directly on the surfaces of the compression plate  4 . Thus, in this embodiment there is no need for a cover. However, the opening  6  is to be covered by a lock or the like (not showed).  
      When the compression plate  3 ,  4  is introduced into the frame  1  ( FIG. 6   a ), the protrusions  5  are first going in the straight part  9  of the grooves ( FIG. 6   b ). As long as the protrusions  5  are in the straight part  9  of the grooves it is not possible to turn the compression plate  3 . For the embodiments having separated rounded and straight parts the compression plate may normally be turned in the straight part. When the protrusions  5  have reached the rounded parts  10  of the groove the compression plate may be turned. As the compression plate  10  is turned it will put pressure on the separate units  2  in the frame and it is also locked from moving along the grooves. The pressure will be transferred from the uppermost partition  13   a  via the separate units  2  and further partitions  13   b  to the lowermost row of separate units  2 . To be able to turn the compression plate  3 ,  4  into a mainly vertical position, i.e. parallel with the main extension of the frame  1 , a tool  14  is placed in the opening  6  ( FIG. 6   c ). The tool  14  may simply be a rod, preferably having a slightly angled end as shown in  FIG. 6 . However, a person skilled in the art realises that any tool may be used, as long as it is possible to give enough force to turn the compression plate  3 ,  4 . The bevelled  7  sides of the compression plate  3 ,  4  makes it easier to turn the compression plate  3 ,  4 .  
      When the compression plate  3  according to the embodiment of  FIG. 3  is in the correct position, the cover  15  is placed in the frame  1  covering the compression plate  3  ( FIG. 6   d ). The cover  15  is placed with the knurl  19  in the opening  6  of the compression plate  2  and the protrusions  20  in the grooves  9  of the frame  1 . The notch  18  of the cover  15  is placed on the uppermost partition  13   a.  Thus, when it has been placed on the compression plate  3 , the cover  15  will seal the compression plate  3  in relation to the frame  1  ( FIG. 6   e ).  
      If the frame  1  is to receive new cables, pipes etc., the above-indicated sequence of operations is reversed. Thus, the cover  15 , if used, is first removed. Then the compression plate  3 ,  4  is turned to a generally horizontal position, whereby the protrusions  5  will turn in the rounded part  10  of the groove. When the compression plate  3 ,  4  has been turned the pressure on the separate units  2  will be relived. The partition  13   a,    13   b  placed above the separate unit  2 , which is to receive a new cable, pipe or the like, may be slid upwards giving access to the desired unit  2 . The separate unit  2  is taken out the cable, pipe or the like is then introduced and the separate unit is adapted to the new cable, pipe or the like. In the shown embodiment this is done in that an appropriate number of sheets are peeled from the separate unit  2 . Thereafter, the unit  2  is place in the frame surrounding the cable, pipe or the like. Finally, the compression plate  3  is once again turned to a vertical position putting pressure on the separate units  2  received in the frame  1 . By means of the induced pressure the separate units  2  will seal the cables, pipes etc. The same line of operations are done if one is to replace one or more of the separate units  2 , either due to damage, that the dimensions are to be altered etc.