Abstract:
A glazed roof comprises glazing bars supporting glazing panels secured to a supporting structure by means of screws through fixing blocks mounted at the glazing bar ends, the fixing blocks having provision for receiving and directing the fixing screws.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    This invention concerns roof construction and, in particular, concerns glazed roof construction, such as for forming a conservatory.  
           [0002]    Conservatory roofs are generally formed from glazing panels supported between glazing bars fixed between a ridge beam and an eaves beam or other side supporting structure, such as a window frame. The glazing bars are usually of aluminum and screws are used to fix the glazing bars to the supporting structure. A difficulty with the use of screws directly through glazing bars is that they can slip as they are being screwed in. That creates particularly difficulties when screwing down ducted glazing bars when the screws are fixed into and through the ducts. Putting the screws through the ducts is better for concealment and neatness but is more difficult practically.  
           [0003]    Another problem with the use of screws directly through glazing bars into a supporting structure is that of cold transference where the glazing bars supporting structure component and the screws are all of metal. When the outside of the conservatory roof is colder than the inside, cold spots and hence condensation can form on the inside of the roof.  
           [0004]    The above problems arise whether the glazing bar is of a type that supports glazing panels on opposite sides thereof or of the type that acts as reinforcement between glazing panels coupled to each other and/or to the glazing bars.  
         SUMMARY OF THE INVENTION  
         [0005]    An object of this invention is to provide an improved glazed roof construction particularly for use in forming conservatory roofs.  
           [0006]    According to this invention it is proposed that a fixing block be mountable at a glazing bar end wherein the fixing block has provision for receiving and directing a fixing screw used to secure the fixing block and hence the glazing bar to a support structure, such as an eaves beam or a window frame.  
           [0007]    The invention also provides a glazed roof wherein glazing bars supporting glazing panels are secured to a supporting structure by means of screws through fixing blocks mounted at the glazing bar ends, the fixing blocks having provision for receiving and directing the fixing screws.  
           [0008]    The fixing blocks are preferably of plastics material, especially PVCu. The fixing blocks are preferably arranged to be a push fit onto glazing bar ends. For a glazing bar that has a single webbed upstand, the fixing block preferably has formations that will sit on either side thereof but for a ducted upstand glazing bar it is preferred that fixing blocks have a formation that is a push fit into the duct of the glazing bar.  
           [0009]    The fixing block of the invention preferably has a through hole for receiving and guiding a screw, the through hole preferably being angled to direct a screw downwardly and towards the roof interior. The through hole is preferably stepped intermediate its ends to provide a stop for the screw head.  
           [0010]    The fixing block of the invention preferably has on its outer end relative to a glazing bar a pair of wings extending laterally. Those wings are intended to act as abutments for glazing panels, whereby adjacent panels can be aligned and slippage can be prevented.  
           [0011]    The fixing block of the invention preferably also has means for attachment of a glazing bar end cap. Preferably the glazing bar end cap is slidably mountable on the fixing block end. The preferred fixing block has a pair of back to back L-shaped brackets. These may be formed by one plate spaced from the fixing block and the glazing bar end cap preferably has a corresponding pair of facing L-shaped projections that can slidably fit onto the brackets of the fixing block.  
           [0012]    The preferred fixing block of the invention has a top formation corresponding to that of the glazing bar to which it is to be fitted, so that a capping for the-glazing bar can also be supported by and/or secured to the fixing block in the same manner as provided by the glazing bar. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]    This invention will now be further described, by way of example only, with reference to the accompanying drawings, in which:-  
         [0014]    [0014]FIG. 1 is a partly cut away perspective view of a conservatory roof;  
         [0015]    [0015]FIG. 2 is another perspective view of the roof of FIG. 1 not cut away;  
         [0016]    [0016]FIG. 3 is a section through the roof of FIGS. 1 and 2;  
         [0017]    [0017]FIG. 4 is a section through a variation on the roof of FIGS.  1  to  3 ;  
         [0018]    [0018]FIGS. 5 and 6 show a conservatory roof gable end partly and fully assembled. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0019]    Referring to FIGS.  1  to  3  of the accompanying drawings, a conservatory roof  10  comprises glazing panels  12  supported between glazing bars  14  secured at one end to a ridge (not shown) and at the other to an eaves beam  16 . The glazing bars  14  are of a type having a ducted upstand  18  into which are push fit fixing blocks  20  of plastics material, typically of PVCu. The fixing blocks have a first part  21  that fits into the glazing bar and second part  23  that remains outside the glazing bar but has a similar outer profile.  
         [0020]    The fixing blocks  20  have an angled screw receiving and guiding hole  24  which is stepped at  25  to have a narrower lower part, the step  25  forming a stop for the head of a fixing screw  26 . The screw  26  is shown securing the fixing block and hence the glazing bar to the head  30  of the eaves beam  16 .  
         [0021]    The eaves beam  16  is generally L-shaped having a double walled upstand  31  and a single walled base plate  32 . The base plate  32  sits on and is secured to the underlying support structure, such as provided by window frames  34 . The head  30  of the eaves beam has a generally arcuate top surface but with a depression  38  therein. The base of the depression has a serrated or roughened surface. Either side of the depression, the head of the eaves beam has two alternative inner and outer areas  42  and  44  respectively on which glazing bars can rest depending on the pitch of the roof. In this embodiment the roof illustrated has a low pitch and so the eaves beam  16  rests on the inner area  42 .  
         [0022]    Interposed between the glazing bars and the eaves beam and lying on the eaves beam is a thermal insulator strip  50  of plastics material. The insulator strip  50  snap fits onto the head  46  of the eaves beam.  
         [0023]    The insulator strip is formed as an extrusion and has a profile generally following the contours of the head of the eaves beam. The insulator strip is provided with ribs  60  on its underside to space inner and outer parts  62 ,  64  thereof from the inner and outer areas  42 ,  44  of the eaves beam head, whilst a central part  66  of the insulator strip sits in the depression in the head of the eaves beam. The inner and outer parts  62 ,  64  of the insulator strip are provided on their top surfaces with double-sided adhesive tape  67  in order to hold the glazing bars  14  in place whilst they are being secured with the screws  26  to the eaves beam.  
         [0024]    Extending forwardly of the insulator strip i.e. towards gutter  70  on the outside of the conservatory is a thin resiliently flexible web  72 . The web  72  contacts the underside of the glazing bar  14  or any bottom capping thereon or the underside of the glazing panels  12  to provide a wind break.  
         [0025]    On its inner end i.e. the end towards the inside of the conservatory, the insulator strip has a lip  74  extending outwardly and then downwardly to form a slot which serves as a top location for internal plastics cladding  76  for the eaves beam  16 . The eaves beam has lower down a fir-tree connector  78  along its length onto which a slot  80  of the cladding is a push-fit.  
         [0026]    The eaves beam  16  supports brackets  82  for the gutter  70  and the leading edge of the base plate  32  of the eaves beam has a push-fit trim  86  thereon, which has a flexible resilient web  88  upstanding to seal between the underside of the gutter and the eaves beam. Furthermore, the trim has a downstand  90  to cover profile features.  
         [0027]    The insulator strip provides a thermal break between the glazing bars and the eaves beam, which otherwise, both being of aluminum, would provide a route for heat loss leading to condensation formation within the conservatory on the eaves beam.  
         [0028]    Ends of the glazing panels are concealed by a channel section trim  100  having a top wall  102 , a bottom wall  104  and a base wall  106 . The top wall  102  has along its edge a co-extruded or bonded gasket  108  of rubber or synthetic elastomeric material to seal against the top surface of the glazing panels. The bottom wall  104  is resiliently deformable to grip on the underside of the glazing panels. The base wall  106  has a spacing rib  110  extending therefrom as has the top wall  112  to leave a ventilation space between the glazing panel ends and the trim base wall. The trim  100  will usually be supplied pre-notched  114  to accommodate the glazing bars (see FIG. 2).  
         [0029]    The glazing panels are held down by cappings  120  that are snap-fits into the tops of the glazing bars and of the fixing blocks whose top profiles match those of the glazing bars. The cappings  120  have depending resiliently deformable formations  122  that are retainable in a channel  124  in the top of the glazing bar having notched side walls the formations having lips that are retained under the notches according to how far the capping is pressed down.  
         [0030]    To conceal the ends of the fixing blocks an end cap  130  is mounted on the fixing block. The fixing block has back to back L-shaped brackets  132  onto which facing L-shaped flanges (not shown) of the end cap can slide downwards until a rim  134  of the cap sits on top of the capping  120 .  
         [0031]    The fixing block  20  further has a pair of laterally extending wings  140  at its forward end from a depending part of the block. These wings are positioned to act as stops for the glazing panels, to position and align them. The wings  140  further act to prevent slippage of the panels in the assembled roof.  
         [0032]    The fixing block enables the screw fixing to be accurately positioned and guided whilst be screwed down making erection of the roof simpler than hitherto.  
         [0033]    Turning to FIG. 4 of the drawings, instead of an eaves beam being used, a PVCu profile  200  is mounted on the window frame  202  and it is to the profile  200  that the fixing blocks  20  and hence the glazing bars  14  are secured by screws  26 . Apart from that the embodiment of FIG. 4 is the same as that of FIGS.  1  to  3 . Like parts have been given the same reference number for ease of reference and will not be described again.  
         [0034]    Finally, FIGS. 5 and 6 illustrate the use of the fixing blocks at the gable end of a conservatory roof  300  made up of ducted plastics panels  302  coupled to the glazing bars  304 . The fixing block and its use are the same as described above together with the attachment of the end cap  308  as shown in FIG. 6.