US 2901785 A
Description (OCR text may contain errors)
p 1959 E. D. HINCHLIFFE ETAL I 2,
GLAZED STRUCTURES AND 'GLAZINC BARS FOR USE IN SUCH STRUCTURES Filed July 8, 1957 4 Sheets-Sheet 1 4AFRE3Z3. k/ooL 1.5V
Sept. 1, 1959 E. D. HINCHLIFFE ETAL GLAZED STRUCTURES AND GLAZING BARS FOR USE IN SUCH STRUCTURES I 4 Sheets-Sheet 3 Filed July 8, 1957 I GLAZED STRUCTURES AND GLAZING BARS FOR USE IN SUCH STRUCTURES Ernest Darby Hinchliife and Alfred Bernard Woolley, West Bromwich, England, assignors to Hills (West Bromwich) Limited, West Bromwich, England Application July 8, 1957, Serial No. 670,518 Claims priority, application Great Britain July 13, 1956 16 Claims. (Cl. 20-56) This invention has reference to glazed structures, particularly glazed wall structures known in the trade as glazed curtain walling, of the kind comprising a framework which is anchored to and externally of the main structure of a building and is constructed from a number of main and auxiliary glazing bars, each of the auxiliary bars being secured to and between two adjacent main bars to provide the framework with rectangular openings each of which is adapted to be closed by a sheet of glass by supporting and securing the marginal zones of the sheet upon the bars defining the opening; the invention is further concerned with glazing bars for use in the construction of the said framework.
Herein, the meaning of the term glazed structure is not to be restricted to structures of the above kind in which all of the openings in the framework are closed by sheets of glass, but is intended to include structures in which only certain of the said openings are so closed, the remainder being closed either by panels which may be opaque, translucent or transparent, or by windows or ventilators having opening lights mounted in frames supported by and secured upon the glazing bars.
The principal object of the present invention is to provide an improved puttyless glazed structure of the kind referred to, which is capable of being erected in minimum time, is weatherproof and permits expansion and contraction of the glazing bars without detriment to the weatherproof character of the structure.
A further object of the invention is to ensure that all connections between the glazing bars are concealed from sight so as to enhance the appearance of the structure.
In accordance with the said invention, a glazed structure comprises a number of parallel main glazing bars to and between which auxiliary glazing bars are assembled at right angles, each auxiliary bar having, at each end thereof, a tongue which passes through an aperture in a lateral wall of one of the main bars and is anchored to the lattter by a keeper plate secured to and between the lateral walls of the said main bar.
Preferably, the tongue is formed with at least one hole which is engaged by a corresponding peg provided on the keeper plate the said plate being secured to threaded studs which are screwed into tapped holes in the centres of transverse straps located on opposite sides of the aperture, the ends of the straps being located in recesses formed in the internal surfaces of the walls by inwardly directed flanges on the edges of the said walls, and being thrust against the sides of the said recesses by screwing the studs on to an end wall of the main bar.
Headed nuts screwed upon the fixing studs of additional and identical straps secured to and transversely of the bar between the apertures, may serve as means for assembling a channel section capping strip to and lengthwise of the main bar, by engaging inwardly extending lips on the internal surfaces of the sides of the said strip under the heads of the nuts so as to grip lateral marginal zones of glazing between resilient cords accommodated in grooves extending along the edgesof the walls of the bar and of the sides of the capping strip.
Each auxiliary bar may be of T-section between the tongues at its opposite ends, and a weather-proofing strip may be secured to the edge of the stem of the bar by resilient bushes which are disposed around bolts engaging tapped holes in the said edge and are compressed between the strip and the crown of a channel section capping strip assembled upon and lengthwise of the bar by the same bolts. The weather-proofing strip may be provided with two wings which project from opposite sides of the stem into overlapping relationship with longitudinally grooved edges of lateral walls on the head of the bar, one wing engaging the groove in one of the said edges and the other being trapped between a side of the capping strip and a marginal zone of glazing seated on a resilient cord accommodated in the groove in the other of said edges.
To permit expansion and contraction of the main and auxiliary bars, the holes in the tongues of the auxiliary bars may be of greater diameter than the pegs on the keeper plate, whereas one end of the main bar may be moveable in the direction of the length of the bars relatively to the main building structure; for example, the said main bar may comprise a base of hollow box section which is adapted to slide upon a spigot-sleeve socketted into one end of the said base.
In order that the invention may be more readily understood and carried into practice, reference will now be made to the accompanying drawings, wherein:
Figure 1 is a perspective view, partly in section, of a joint between a vertical bar or mullion and two horizontal bars of transoms, of a glazed curtain walling.
Figure 2 is an exploded view of the joint, certain parts having been omitted.
Figure 3 is a section, on an enlarged scale, along the line a--a, Figure 1.
Figure 4 is a section along the line b h, Figure 3.
Figure 5 is a section, on the same scale as Figure 3, along the line cc, Figure 1.
Figure 6 is a section, on a still larger scale, along the line dd, Figure 1.
Figure 7 is a vertical section through the adjacent ends of two main bars used in the erection of a mullion, and
Figure 8 is a section along the line ee, Figure 7.
The joint shown in Figures 1-5 is part of a glazed curtain walling comprising any desired number of vertical mullions 1 which are pitched apart by any predetermined distance, and a number of horizontal transoms 2 each of which is connected to and between two adjacent mullions, two or more transoms being provided between each of the said adjacent mullions at predetermined intervals apart along the length of the latter. Each of the mullions may be of any desired length and may extend between two or more floors of a building, or from the ground level to any floor or the roof eaves of the building as desired; when the length of a mullion is in excess of a predetermined maximum, preferably it is built up from two or more sections which are connected end-to-end in vertical alignment.
The interconnection of the vertical mullions and horizontal transoms provides a framework having a number of rectangular openings, and each opening may be closed by a sheet of glass 3 of which the peripheral zones are supported by mullion portions and transoms defining the opening. Alternatively, as and where desired throughout the framework, certain of the openings may be closed by panels or by opening windows or ventilators, the panels and the frames of the windows or ventilators being supported by the mullions and transoms in the same manner as the glass sheets. i
The framework erected from the assembly of mullions and transonis is adapted 156 be assembled to the main striietiire of a building in any desired manner, for example, by anchoring each mullion to the said structure at, each floor and/or ground and/or roof eaves level. E565 vertical n'iiillidr'i or mulliori section comprises a main glazing bar 4 which is located on the inside of the Walling so that it is not exposed to weather, and a capstrip 5 which is located on the outside of the walliiig is exposed to weather, the said bar and strip jiir efeiably consisting of aluminum extrusions. The bar 4 is formed with a base of hollow box-like section, the
wall 6 of the said base adjacent the glazing being wider than its opposite end wall 7, and the side walls is being relatively inclined from the vicinity of the wider end wall so that the base comprises a root portion of tiinrofin width and then tapers to the narrower end wall. rheparana sides 6f the root portion extend beyond the wider wall and each extension is formed along its fi e edge with aninw a'rdly directed flange 9 having in edge adjacent the glazing 3, a longitudinal groove 10 of inverted-V or dovetail section in which a resinbonded or like resilient cord 11 is accommodated; the said cords project beyond the flanges so as to provide resilient beds for the internal surfaces of the lateral edge zones of the said glazing. By providing the flanges 6n the sidewall extensions, two longitudinal channels are formed internally of the said extensions, the said ehannels being disposed mouth-to mouth and being of the same uniform depthand width.
At each position along the main bar at which a .transorn is connected, an aperture 13 is formed in the extension of the corresponding side wall 8, the said aperture opening to the flanged edge of the said extension and reaching to the external surface of the wider end wall '6 (see Figure 2). When, asshown in the drawings, two transoms located on opposite sides of the main bar are connected to the said bar in transverse alignment, a
pair of identical registering apertures 12 is formed in the extensions of the side walls 8. I
Each horizontal transom comprises an auxiliary glazing bar 13 and a capping strip 14, each of which also preferably consists of an aluminium extrusion.
The bar 13 is approximately T-shaped in cross section except that, at each end thereof, the stem 15 is cut ifrom the head in the same direction as, and parallel to,
the stem 15, an inturned'flange 19 having a groove 29 in its outer surface, is formed along the -free edge of each of the walls, and an asbestos or similar cord 21 is accommodated in and projects from the groove 20 which is disposed below the stern so as to provide a resilient bed for the upper-marginal zone of a comefsponding glazing sheet 3. The tongues 17 seat upon the external surface of the wider walls 6 of the main bars, and the extensions of the side walls 8 are of the same depth as the side walls 18 so that the grooved flanges 9 and 19, and the cords 1'1, "21 accommodated therein, are flush with one another and the glazing beds simultaneously on'the said cords. ;A hole 17a is formed in each tongue 17 in the plane of the stem 15.
To anchor the auxiliary bars to the main bars, metal straps 22 are secured between the extensions of the side walls 8 on opposite sides of the registering pair of apertures 12. The straps are of an overall lengthequal to the distance between the adjacent surfaces of the said extensions so that their opposite ends extend'respectively into the channels 1a, abut the said surfaces and are disposed between the said flanges andthe end wall 6. Since the strap ends abut the wall extensions, -movement of the straps transversely of the main :bar is prevented and therefore tapped holes 23 formed in and centrally of each of the said straps are located in the longitudinal centre line of the bar. A threaded stud 24 (see Figure 2) is screwed into the central tapped hole of each strap and on to the external surface of the wall 6, thereby forcing the strap ends against the flanges 9'to lock the straps to and transversely of the bar; the studs are of a length such that they project beyond their respective straps, and the side wall extensions (see Figure 2) so that two holes 26 in a keeper plate 25 may be engaged respectively with the studs. The width of the keeper plate is equal to the distance between the adjacent edges of the flanges 9 and two transversely aligned pegs 27 are provided on and midway between the ends of the said plate; upon engaging the holes 26 with the studs 24, the plate passes between the flanges on opposite sides of the apertures 12 and seats upon the straps and the tongues of the auxiliary bars, and the pegs 27 engage respectively with the holes 17a in the said tongues; the plate is then secured in position by screwing nuts 28 on to the studs (see Figure 3). The pegs are of a diameter less than the diameter of the holes 17 so that, although the engagement of the pegs in the holes anchors the auxiliary bars to the main bar, nevertheless the difference between the said diameters permits expansion and contraction of the auxiliary bars.
The keeper plate is formed, on each lateral edge thereof, with an ear 29 which fits within the corresponding aperture 12,, and is formed with an upstanding lip 30 which is disposed in longitudinal alignment with the outer side of the corresponding longitudinal groove 10 so that the cord 11 extends across the said ear in contact with the said lip.
A flashing strip 31 having holes 32 which are pitched apart by the same distance as the holes in the keeper plate and which also engage the threaded studs 24, is superimposed and seated upon the said plate by the nuts 28. The lateral edges of the strip are bent out of the plane of the strip and away from the plate to form longitudinal grooves 33 which receive the inner sides of the grooves 10 so that between the apertures 12, the free and outer sides of the strip grooves abut the cords 11 thereby ensuring that the said cords remain in contact with the lips 30. The grooves terminate short of the upper end 31a of the strip and this upper end is turned over towards the wall 6 through an angle in excess of ninety degrees (see Figure 3) into contact with the Wall to .provide a pocket which is filled with mastic or other waterproof material 34 to ensure that any water which may gain access to and flow down the said wall, "is directed over the strip and is prevented from gaining access to the underside of the keeper plate from where it could seep through the apertures 12 to theinterior of the walling.
To facilitate the engagement of the straps 22 in the channels 1a, each end of each strap is formed with a portion 22a which is at right angles to the longitudinal cen'tre'line of the'strap and abuts the internal surface of the extension of the corresponding wall 8, and a charnfered portion 22b,'the said inclinedportions extending from the opposite longitudinal edges of the strap.
Having anchored the auxiliary bars of each framework joint to the-corresponding main bar, a weatherproofing strip 35 of approximate Z-section, and of the same length as the-auxiliary bars, is applied to the stem 15 of each'auxiliary bar. The saidstrip is formed with 'a'channel along the root of one wing 36 and the said channel is socketed onto the =free-edge of the stenrso that the wing 36 and theother wing 37 project from the opposite sides of and at right angles 'to the stem: the
--depth of the channel-is such that the wing 36 is spaced from the cord 21 in "the lower channelled flange 19 of the bar by a distance substantially equal to the'thickness of the .glazing 3; however, the wing- 37 is level with the *upper flange g19=of the said bar and its extremityiover- 52 laps the groove in the said upper flange and is curved so that it enters and seats upon the internal surface of the groove: a layer 38 of mastic or similar waterproof substance is applied to the upper face or the strip and the surface of the wing 37 remote from the head of the bar. 1
Each sheet of glazing is inserted into the corresponding rectangular opening of the framework by sliding its upper marginal zone between the cord 21 and wing 36 of the weather-proofing strip applied to the auxiliary bar extending across the head of the opening, seating the opposed lateral zones upon the cords 11 of the main bar portions extending along each side of the opening, and bedding the lower marginal zone in the mastic or like layer 38 on the weatherproofing strip applied to the auxiliary bar extending across the bottom of the opening, the sheet being retained temporarily in position by clips 39 (see Figure 3) applied to threaded studs 24a whereby additional straps 22c, identical to the straps 22 are fixed in and transversely of the main bar between the said upper and lower auxiliary bars by headed nuts 40 screwed upon the said studs and projecting between and beyond the glazing 3 located on opposite sides of the mullion.
The fixing of the glazing is made permanent and weatherproof by assemblying the capping strips 5 and 14 to the main and auxiliary bars respectively.
The capping strip 5 of each mullion is of channel section, its mouth being of uniform width for a fraction of the depth of the strip by forming each of the two sides with parallel portions 5a which are perpendicular to the glazing 3, the remaining portions 5b of the said sides being relatively inclined so that the strip tapers towards its base 50. The free edge of each side 5a, 5b is formed with a longitudinal and internal flange 5d having in its outer face an inverted-V or dovetailed groove in which a plastic or like cord 39 is accommodated. The said cord is formed with two diverging wings 39a which are pressed upon the surfaces of the glazing on opposite sides of the mullion and thereby prevent water seeping between the capping strip and the glazing. A lip 52 projects from each flange 5d inwardly of and towards the longitudinal centre line of the capping strip, the said lip being inclined towards the base 50 and the two lips terminating at equal distances: from and on opposite sides of the said centre line. The nuts 40 screwed on to the additional threaded studs 24a have tapered heads 40a and necks 40b of smaller diameter than the said heads which are of a diameter in excess of the distance between the adjacent edges of the inclined lips 5e. Since the holes 23 in the centres of the straps 220 are located in the longitudinal centre line of the main bar, and the lips 5e' are disposed equidistantly from the longitudinal centre line of the capping strip 5, the lips will engage and ride over the nut heads 40a as the strip is applied to the glass sheets, to centralize the strip relatively to the bar and, as the strip is pressed upon the glazing, the wings 40 of the cords 39 are flexed outwardly and the lips 5e snap under the nut heads to secure the strip resiliently upon the glazing in symmetrical relationship to the bar.
The horizontal capping strips 14 are also of channel section, are of a depth which is substantially equal to the depth of the mouth portions 5a of the capping strips 5, and are of a length equal to the distance between the said mouth portions of strips incorporated in the two adjacent mullions to which the transoms are anchored. The upper side of each horizontal capping strip comprises a downwardly inclined portion 14a which extends to the crown 14b of the strip, countersunk holes 14c are formed in the said crown at intervals apart equal to the intervals between tapped holes 15a in the edges of the stems 15 and holes 35a in the base of the channelled portion of the weather-proofing strips 35, in-
:wardly directed lips 14d are formed along the free edges 6", of'both sides of the strip, and drainage holes114e are formed in and at intervals along the length of the lower side of the strip.
The inverted frusto-conical head 42 of a resilient bush 41 is held within each countersunk hole in the crown of the horizontal capping strip, so that the bush is held internally of the strip and abuts the edge of the stem 15 as the strip is applied to the corresponding auxiliary bar. By aligning the bores of the bushes in the capping strip, with the registering holes 15a and 35a in the stem and weatherproofing strip respectively, bolts 43 may be passed through the said bores, and holes 35a may be screwed into the tapped holes 15a to secure the capping strip to the horizontal bar with the ends of the said strip in close proximity to the flat side portions 5a of the vertical capping strips, with the lip 14d on the upper side of the strip 14 in contact with the lower marginal zone of the glazing sheet 3 secured above the transom, and with the lip 14d on the lower side of said strip in abutment with the wing 36 of the corresponding weatherproofing strip. By screwing the bolts 43 as far as possible into the tapped holes, the bushes are compressed and the lips 14d are pressed towards the outer surfaces of the glazing 3 thereby restricting any tendency for water flowing down the outside of the said upper glazing sheet to seep between the surface of the upper sheet and the upper side of the strip 14. Nevertheless, any water which may gain access to the interior of the capping strip is prevented from seeping to the interior of the walling by the weatherproofing strip 35 and mastic or like layer 38, is free to flow through the clearance formed between the crown 14b of the strip 14 and the channelled portion of the strip 35 by the bushes 41, and then be discharged through the slots Me.
To permit expansion and contraction of the mullions without detrimentally affecting any of the Weathertight seals made in the walling, the head of each mullion section makes a sliding engagement with the foot of the next adjacent higher section, and the head of the uppermost section makes sliding engagement with a fixture provided on the main structure of the building. For example, as shown in Figures 6 and 7, the adjacent ends of the main bars of the two adjacent mullion sections are tied respectively by bolts 44 and 45 to a bracket 46 fixed in any convenient manner to the main structure (not shown), and the opposite ends of a spigot-sleeve 47 socket into the adjacent ends of the hollow bases of the said bars. The bolt 44 passes through a slot 48 in and lengthwise of the narrower end wall 7 of the base of the lower bar, and a similar slot 49 in and vertically of the bracket so that the head of the lower bar is capable of sliding relatively to the bracket in a direction along the length of the bar. However, the bolt 45 passes through and fits within holes 50, 51 formed respectively in the foot of the narrower end wall 7 of the upper bar and the bracket so that the said foot is fixed relatively to the bracket end therefore to the main structure of the building.
A somewhat similar connection is effected between the capping strips 5 of the two aligned mullion sections by a tapered channel section spigot 52 which fits within and is retained resiliently within the adjacent ends of the said strips; relative longitudinal movement between the spigot 52 and the strips is limited by providing the said spigot with a nose 53 which projects into the clearance between the crowns of the said strips.
A flashing strip 54, similar to the flashing strip 31, is assembled to the foot of the upper bar, by engaging two holes therein with the threaded studs 24a securing two additional straps 220 against the flanges 9 of the said foot, and securing the said strip upon the said studs by taper-headed nuts 40. The strip 54 extends between the flanges 9 of the head of the lower bar but is not secured to the said head which is therefore free to slide relatively to the said strip when the bar is expanding or contracting. The upper end 54a of the flashing strip '54 is bent over into contact with the external surface of the wider end wall 6 of the upper bar and is sealed with a layer 54b of mastic or like waterproof substance, whereas the lower end 540 of the strip is bent over through an angle less than ninety degrees into contact with the wall 6 of the lower bar so that any water flowing down the wall 6 of the upper bar is conducted on to, and flows down, the flashing strip on to the wall 6 of the lower bar and is prevented from gaining access to the clearance between the adjacent ends of the two bars.
The head of the uppermost section of each mullion is socketed in to and makes sliding engagement with a spigot sleeve (not shown), similar to the sleeve .47, depending from a bracket fixed to the main structure at the top of the walling.
In the joint shown in Figures 1-5, two aligned and horizontal transoms are anchored to the vertical mullion; however, in some of the joints (not shown) of the framework a single transom only is connected to a mullion; in such joints, the main bar is formed with a single aperture 12 to receive the tongue 17 of the transom bar 13 and the keeper plate 25 is formed with a single lipped car 29 which fits within the aperture; otherwise, the joint is effected in the same way as the joint shown in the said Figures l-5.
If desired, instead of producing each main bar 4 in one piece, the wider end wall 6 and the extensions of the side walls 8 may form one unit and the said side walls and the nanrower end wall 7 may form a second unit, the said first unit being provided with parallel lateral lips which socket into the mouth of and are bolted or otherwise assembled to the second unit. Such a construction permits the cross section and, therefore the strength, of the bar to be varied by replacing the second unit by an alternative unit having-diiferent cross sectional dimensions.
What we claim is:
1. A glazed structure wherein auxiliary glazing bars are assembled to and between and at right angles to a number of parallel main glazing bars, a plurality of apertures in a lateral wall of one of the main bars, a keeper plate, each auxiliary bar having, at each end thereof, a tongue which passes through one of said aper- 'tures in the lateral wall of one of the main bars and is anchored to the latter by said keeper plate secured to and between the lateral walls of the said main bar.
2. A glazed structure as claimed in claim 1 wherein each tongue of the auxiliary bar is formed with at least one hole which is engaged by a peg on the keeper plate.
3. A glazed structure as claimed in claim 1 wherein the keeper plate is fixed upon the main bar by threaded studs which pass through holes in the plate into engage ment with straps locked to and transversely of the walls of the said bar on opposite sides of the aperture, and
by nuts screwed on to the said studs.
4. A glazed structure as claimed in claim 1 wherein the main bar is provided with lateral and coextensive lateral Walls in each of which a number of tongue- "receiving apertures is formed, the internal surface of each wall having recess therein on the opposite sides of each aperture, the corresponding recesses on each side of each aperture being engaged by the opposite ends of a strap having a tapped hole in the centre thereof, the
said hole being engaged by a threaded stud which is screwed down on to the bar to force the strap ends gagainst'the edges of the recesses remote from the bar,
and-a plate disposed between the said walls and having at 'leastone peg which engages a hole in the tongue of an auxiliary bar insertedthrough the aperture, :being fixed Ito the strap securing studs on opposite sides of the :aperture.
5. A 'glazedt structure :as claimed in claim 4, wherein "theirecesses consist of channels which, initially, are co- 8. extensive withthe bar walls but are interrupted by the formation of the tongue-receiving apertures.
,6. A-glazed'strueture as claimed in claim 4, wherein from the bar with an inwardly directed flange to which each .of the bar walls is provided along its edge remote each aperture in the said Wall opens, and which has a groove in and extending lengthwise of its outer surface, the plate fits within the clearance between the two flanges and has, on at least one edge thereof, a laterally projecting ear which fits within a corresponding one of the apertures with its face remote from the bar flush with the base of the groove, the said car being provided with a lip which is in longitudinal alignment with the outer side of the groove so that .a resilient cord accommodated in the groove and spanning the aperture, contacts the inner face of the lip.
7. A glazed structure as claimed in .Claim 6 wherein a flashing strip engages the strapsecuring studs and seats upon the face of the plate remote from the main bar, the lateral edges of the said strip being formed into grooves of which the outer. sides engage the cord-acco d modating grooves in the flanges so that one of the said outer sides spans the lipped ear in contact with the side of the corresponding cord opposite to the lip, and wherein at least one end of the strip projects beyond the plate and is turned over towards the bar through an angle greater than ninety degrees and contacts the said bar.
8. A glazed structure as claimed in claim .3 wherein additional straps are fixed to and transversely of the sides ofthe main bar between the apertures, by threaded studs bearing upon the bar and projecting away from the bar beyond the straps, headed nuts screwed on to the said projections being engaged by inwardly directed lips provided on and internally of the sides of a capping strip extending lengthwise of the bar, to attach the said strip to the bar.
9. A glazed structure as claimed in claim 8, wherein the free edge of each side of the capping strip is grooved longitudinally thereof and a resilient cord is accommodated within and along the length of each groove so that a marginal zone of glazing inserted between one of the flanges and a corresponding side of the capping strip, is gripped between the cords in the said flange and side respectively.
1.0. A glazedstructure as claimed in claim 2 wherein the peg on the plate -is of smaller diameter than that of the hole in the tongue to permit relative movement between the tongue and plate due to expansion and contraction of the awdliary bar.
11. A glazed structure as claimed in claim 1 wherein one end of the vmainbar is anchored relatively to a main structure to which the g azed structure is assembled and the Opposite end of the bar is moveable in the direction of the length of the said bar, relatively to the said main structure due to expansion and contraction of the bar.
12. A glazed structure as claimed in claim '1 1, wherein the main bar comprises at least two aligned sections, one of the adjacent ends of the two sections ,is fixed and the other of said ends is slideahle relatively to the main structure, both ends being socketed on to a common spigot, and being spanned by a flashing strip which extends between the lateral walls of both sections, has longitudinally groove lateraledges which engage grooves formed in and longitudinally of the edges of said walls and is fixed to one of the said adjacent ends.
13. vA glazed structure as claimed in claim 1, wherein each auxiliary bar is of T-section between the two end tongues, the edges of'the head of the bar is provided with walls which project therefrorn on opposite sides of, in the same direction as, and parallel to the stem of the bar, each of the said :walls having a grooveformed 'in and longitudinally of its edge and one of the said grooves accommodating :a resilient cordwhich is co-planar with cords accommodated in longitudinal grooves in the edges of the walls of the main bar.
14. A glazed structure as claimed in claim 13 wherein a weather-proofing strip of Z-section extends lengthwise of each auxiliary bar between two adjacent main bars, the wings of the said strip extending to opposite sides of the stem with one wing overlapping and spaced from the cord accommodated in the one wall and the other wing overlapping and contacting the grooved edge of the other Wall of the said bar.
15. A glazed structure as claimed in claim 14, wherein the weatherproofing strip is secured to the stern of the auxiliary bar by bolts passing through the crown of a channel section capping strip into engagement with 10 tapped holes in the edge of the stem, and by resilient bushes disposed around the bolts between the said crown and stem, the said bolts also securing the said strip to the bar.
16. A glazed structure as claimed in claim 1, wherein each main bar comprises a hollow box-like section base from each end of one wall of which the apertured walls project at right angles.
References Cited in the tile of this patent UNITED STATES PATENTS