Patent Publication Number: US-2007107332-A1

Title: Modular framing system

Description:
FIELD OF THE INVENTION  
      The present invention relates to a framing system installable around cables and conduits. More particularly, the invention relates to a modular framing system which does not require nailing and which offers a possibility of adaptation to the configuration and location of cables and conduits installed in underground networks structures.  
     BACKGROUND OF THE INVENTION  
      Underground networks such as electrical distribution networks, telecommunications networks, cable television networks and the like comprise structures which must sometimes be replaced. These structures that are buried in the. ground can be manholes, access chambers, access vaults, junction box and others.  
      One of the reasons that forces to replace the existing structures is the premature deterioration of the material (concrete or bricks) used at the time of the original construction. Another reason that forces to replace the existing structures is to comply with new requirements established for reasons of maintenance, safety, ergonomics and/or addition of equipment.  
      For the majority of the users, putting a network out of order even for a temporary period is not an option because numerous residential and commercial subscribers (read“customers”) would be deprived of essential services. Any interruption of this type would prove to be extremely expensive for the subscribers. Some of these subscribers are hospitals, buildings with offices or shops which cannot interrupt their activities.  
      Consequently, the users are forced to develop working methods that would allow them to carry out different modifications while keeping the networks functional during the work.  
      An existing method currently used at building sites consists in demolishing the existing structure and rebuilding a new structure while maintaining in service the existing underground networks. As an example, mention can be made of Hydro-Quebec which maintains its electric supply underground cables functional in their original positions, during all the steps of demolition and reconstruction. Mention can also be made of other societies which use access vaults (junction box) in which one finds electrical cables, telecommunications cables as well as television cables. These cables are usually naked inside the access vaults, but contained between one access vault and another in PVC (PolyVinyl Chloride) conduits which are generally embedded in concrete (such are also called “concrete duct”).  
      The existing method used in this case comprises two parts, the first one being the demolition and the second one being the reconstruction.  
      During the demolition, the following steps are carried out: 
          excavating and removing the material that covers and/or surrounds the structure;     installing inside the structure, a false self-bearing wooden roof under the ceiling of the structure (this false roof is used to protect the equipment inside the structure during the demolition);     demolishing and removing the chimney of the structure;     demolishing and removing the ceiling (roof) of the structure;     installing a horizontal beam (made of steel and/or of wood) on the surface of the street directly to the top of the structure (in the same alignment as the existing cables);     installing nylon cords attached to the beam for supporting the cables;     demolishing and removing the vertical walls and the floor of the structure; and     demolishing and removing the concrete of the duct on a few meters on each side of the structure (this gives some flexibility to move the cables in a safe manner while the workers are working).        

      During the rebuilding, the following steps are performed: 
          excavating the ground to fit the dimensions of the new structure;     preparing the foundation for the new structure;     assembling and levelling a framing to form the floor;     pouring concrete to form the floor;     assembling a framing to form the vertical walls. During this step, the contractor must girdle the existing cables. To do so, wood boards must be cut to form semi-circle openings which are then laid out on both sides of each existing cable. Also, bell shaped PVC components must be cut and placed on both sides of each cable (bell shaped PVC components offer a soft surface for pulling the cables). This step requires a great dexterity from the workers because they handle nails and hammers near electric cables under tension.);     installing PVC conduits around the existing cables, these conduits extend from the structure up to the still intact concrete duct, (conduits cut in half over their length are used to carry out this task;     pouring concrete to form the vertical walls;     preparing a framing for the concrete duct;     pouring concrete to form the concrete duct;     installing a framing to form a new roof into the new structure (To carry out this step, the contractor must install beams resting on the floor of the structure to support the framing in which the concrete will be poured to form the new roof. These beams have to be installed through the existing electrical cables without touching or damaging them.);     pouring concrete to form the roof;     assembling a framing to form the chimneys;     pouring concrete to form the chimneys;     letting the concrete harden;     installing the embankment material;     assembling a framing to form the sidewalk;     pouring concrete to form the sidewalk and asphalt for the paving; and     restarting public services (sidewalk, paving, circulation lane, etc).        

      As may be noticed, the existing method described above requires a long intervention time of the workers, which increases the risks of injuries, particularly when the workers are close to electrical cables under tension. In the last case, the workers must indeed sometime manipulate nails and hammers around electrical cables under tension.  
      Thus, there is a need for a safer and faster method to build framings and to pour concrete around cables.  
     SUMMARY OF THE INVENTION  
      The object of the present invention is to provide a modular framing system that satisfies the above-mentioned needs.  
      More particularly, the present invention is directed to a framing system devised to fit around elements entering into a concrete structure via an opening through which one wants to pour concrete, this system comprising 
          angle-bars attachable to two opposite sides of the opening inside the concrete structure, the angle-bars having tongues;     modules fittable into each other to cover the whole opening, the modules engaging the angle-bars and being held in place by the tongues of the angle-bars, one or more of the modules comprising recesses adapted to the geometry and the size of the elements entering into the structure to fit on them; and     panels intended to be installed outside of the concrete structure to complete the framing and allow pouring of the concrete.        

      Preferably, each module comprises a panel connected to a support system. The recesses provided in the modules are then located in the panels of the modules and each have a semi-circular shape.  
      Preferably also, blocking means are added to the tongues of the angle-bars to fix the modules to the angle-bars.  
      The invention is also directed to a method for installing a framing around elements entering in a concrete structure via an opening through which one wants to pour concrete, comprising the steps of: 
          a) inserting anchoring means into two opposite sides of the opening through which the elements enter into the concrete structure;     b) installing angle-bars having tongues on the two opposite sides of the opening inside the concrete structure by means of said anchoring means;     c) installing modules fitting into each other to cover the whole opening, the modules engaging the angle-bars and being held in place by the tongues of the angle-bars, one or more of the modules comprising recesses adapted to the geometry and the size of the elements to fit on them;     d) covering the elements which are not conduits with non-conducting waterproof tubes;     e) installing bell shaped components around the elements covered with a tube, the components being made of a non-conducting waterproof material and having a broad part that is pressed on the corresponding module;     f) installing panels outside the concrete structure to complete the framing;     g) pouring concrete in the framing that is so completed; and     h) dismounting the modules, the angle-bars and the panels which are outside the concrete structure.        

      Preferably, in step c, the modules are fixed to the angle-bars by blocking means fitting to the tongues.  
      Preferably also, in step g, the concrete is poured through the opening.  
      Advantageously, the method can also comprise the additional step of pouring concrete around the exposed elements outside of the concrete structure in order to coat these elements.  
      The invention and its advantages will be better understood upon reading the following non restrictive description of a preferred embodiment thereof made with reference to the accompanying drawings.  
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a top plan view of a concrete structure comprising two modular framing systems according to a preferred embodiment of the invention.  
       FIG. 2  is a cross sectional view of the blocking means used in the modular framing systems according to the preferred embodiment of the invention.  
       FIG. 3  is a side elevational view of the angle-bar used in the modular framing systems according to the preferred embodiment of the invention.  
       FIG. 4  is a front elevational view of the first modular framing system illustrated in  FIG. 1 .  
       FIG. 5  is a top plan view of the first modular framing system illustrated in  FIGS. 1 and 4 .  
       FIG. 6  is a top plan view of the second modular framing system illustrated in  FIG. 1 .  
       FIG. 7  is a front elevational view of a center module of the modular framing systems according to the preferred embodiment of the invention.  
       FIG. 8  is a side elevational view of the center module illustrated in  FIG. 7 .  
       FIG. 9  is a top plan view of the center module illustrated in  FIGS. 7 and 8 .  
    
    
     DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT  
      In the following description, similar components shown in the drawings have been given similar reference numbers. In order to make the figures simpler, some components have not been identified in some figures if they had already been identified in a precedent figure.  
      The basic object of the invention as shown in the drawings is to eliminate the use of nails and hammers and to reduce the intervention time of the workers, especially when they are working in presence of electrical cables under tension.  
      The modular framing system ( 1 ) according to the preferred embodiment of the invention as illustrated in the annexed drawings is conceived to be easily adapted to the various realities met on building sites. This system comprises angle-bars ( 10 ,  12 ,  14 ), modules ( 2 ,  4 ,  6 ) and panels. The modules ( 2 ,  4 ,  6 ) are devised to be juxtaposed according to the users. The system is fixed to a concrete structure (access chamber, access vault, junction box and other) to build a framing around existing cables or conduits.  
      In order to fix the modular framing system ( 1 ) to the concrete structure ( 40 ), anchoring means ( 20 ) such as anchor sleeves can be installed in the concrete structure. If the concrete ( 34 ) required to complete the installation must be poured towards the outside of the existing concrete structure ( 40 ), then the sleeves ( 20 ) must be installed to the interior side of the concrete structure ( 40 ). Thus the modular framing system ( 1 ) will be located inside the concrete structure ( 40 ) opposite to an opening and the concrete ( 34 ) will be able to be poured in the opening towards the outside of the concrete structure.  
      The angle-bars ( 10 ,  12 ,  14 ) which are preferably made of steel are then installed to the concrete structure ( 40 ) using fastening means ( 24 ) such as bolts. The bolts can then be passed through holes ( 8 ) made in the face of the angle-bars which are resting against the concrete structure ( 40 ) and can then be screwed into the anchor sleeves ( 20 ) pre-installed in the concrete structure. The angle-bars can also be provided with tongues ( 26 ) which are used to hold the modules ( 2 ,  4 ,  6 ).  
      The modules ( 2 ), center modules ( 4 ) and end modules ( 6 ), which are adapted to the design of the building site (existing and futures cables and conduits) may comprise panels ( 18 ) having their back face preferably made out of polyethylene. These panels can also comprise a strip ( 28 ) to fit them into each other. These modules ( 2 ,  4 ,  6 ) can be provided with a support system ( 16 ) engaging in the angle bars ( 10 ,  12 , 14 ).  
      Blocking means ( 22 ) added to the tongues ( 26 ) can be used to fix the support system ( 16 ) of the modules ( 2 ,  4 ,  6 ) to the angle-bars ( 10 ,  12 ,  14 ).  
      In practice, the modular framing system is installed in several steps.  
      The first step consists in inserting anchor sleeves ( 20 ) into two opposite sides of an opening devised to allow passage of the existing cables in the concrete structure ( 40 ). The sleeves ( 20 ) will be used as anchoring means for the modular framing system ( 1 ).  
      The second step carried out on the building site, consists in installing the angle-bars ( 10 ,  12 ,  14 ) preferably in vertical position on both sides of the opening through which the existing cables enter the concrete structure. Bolts ( 24 ) can then be passed through the holes ( 8 ) of the angle-bars ( 10 ,  12 ,  14 ) and screwed in the anchor sleeves ( 20 ) inserted in the first step.  
      The third step consists in installing the modules ( 2 ,  4 ,  6 ) which fit into each other and comprise recesses adapted to the geometry of the existing cables, preferably in horizontal position. These modules ( 2 ,  4 ,  6 ) are preferably horizontal and are fitted into each other thanks to their stips ( 28 ).  
      The modules ( 2 ,  4 ,  6 ) are preferably engaged into the angle-bars ( 10 ,  12 ,  14 ) and are held in place by the blocking means ( 22 ). The modules are thus held in place until the removal of the framing which follows the pouring and hardening of the concrete ( 34 ) on the building site. The back face of each of these modules ( 2 ,  4 ,  6 ) is preferably made of polyethylene (non-conducting material) to avoid any risk of electrocution when the workers handle them.  
      The fourth step, optional if no cable enters into the concrete structure ( 40 ) by the opening, consists in covering the cables with tubes preferably made of PVC ( 30 ). For this purpose, one can use tubes cut in half along their length.  
      The fifth step, optional if no cable enters the concrete structure ( 40 ) by the opening, consists in installing bell shaped components preferably made of PVC ( 32 ) around the existing cables. These bell shaped components ( 32 ) are preferably pressed on the corresponding modules ( 2 ,  4 ,  6 ) of the modular framing system ( 1 ), the broadest part of the components pressed on the corresponding modules. The tubes ( 30 ) and bell shaped components ( 32 ) can be maintained in place during the pouring of the concrete by short lengths of PVC conduits preferably introduced into the bell shaped components ( 32 ) from the interior of the concrete structure ( 40 ).  
      The sixth step consists in installing panels outside the concrete structure ( 40 ) to complete the framing. These panels are used to retain the concrete at the time of pouring.  
      The seventh step consists in pouring concrete ( 34 ) in the framing, preferably through the opening of the concrete structure ( 40 ).  
      The eighth step consists in dismounting the modular framing system ( 1 ), when the concrete has hardened. The work is then completed.  
      The advantages of the invention are the following: 
          no cutting of the framing is required to girdle the electric cables under tension;     no nailing is required near the electric cables under tension;     a very limited presence of workers is required near the electric cables under tension;     the work is standardized for all contractors (increased safety);     the horizontal and vertical pitches between the conduits (cables) are also standardized;     there is an adaptability between existing and future cables; and     the system can also be used when there are no conduits.        

      It goes without saying that numerous modifications could be made to the preferred embodiment of the invention which has just been described, without departing from the scope of this invention such as defined in the annexed claims. Thus, for example, in the preferred embodiment described hereinabove, reference has made to bolts, anchor sleeves, sleeves, tongues, panels, strips, support system, PVC tubes, bell shaped PVC components, concrete, concrete structures, anchoring means, blocking means, fastening means, horizontal modules, vertical modules, angle-bars, polyethylene, etc. It has to be understood that the structures and geometrical configurations of the components described hereinabove are not essential to the invention and should not be taken in a restrictive way to limit the scope of this invention. It would actually be obvious for any person of the art that other components, other types of cooperation between the components as well as other geometrical configurations could be used for the modules, the angle bars, the anchoring means, the blocking means, the support system, the panels, the strips, the tongues, the conduits and the bell shaped components made of PVC, etc.