Balustrade construction

This invention relates to building construction from pre-fabricated units, and more particularly to the construction of balustrades or the like from extruded components of such materials as aluminium or its alloys.

BACKGROUND OF THE INVENTION 
It is known to clip together baluster modudules to produce a sub-assembly 
to which is afterwards clipped a top rail. 
Certain disadvantages of the above-mentioned system included the need to 
punch or drill holes in the modules and the need for a continuous top 
rail. The present invention dispenses with the need for the formation of 
holes and the absence of a continuous top rail, at least in one 
embodiment, ensures that the modules before assembly may be packed into a 
container and transported with ease, or even supplied in the form of a 
`do-it-yourself` kit for subsequent assembly by amateurs or other persons 
of limited skill. In one embodiment of the invention, described 
hereinafter, it is merely necessary to instal eight screws to assemble the 
outside frame of a balustrade. The remainder of the assembly simply clips 
together without the use of tools. 
The invention is also an improvement in certain other prior known systems 
including that which is the subject of Commonwealth Specification No. 
477,021 by Charles G. Young, wherein the clipping method if dependent upon 
the formation of a baluster of complex section necessary to admit it to an 
accepting channel, within which it is turned to wedge it between two 
inwardly-projecting lips of that channel. This arrangement requires the 
formation of cuts in opposite sides of each baluster, these cuts being 
made normal to the co-acting grooves. 
Attempts have been made to improve the last-mentioned arrangement by 
sliding balusters lengthwise into the upwardly-facing mouth of a channel 
member forming the bottom rail of a balustrade and then sliding a lid or 
closure strip into a grooved section of the channel before pressing it up 
against the `downstream` end of a last-assembled baluster, and so on. Such 
a system has suffered from the disadvantage, however, that a gap always 
existed beside each baluster which tended to admit water and other foreign 
matter. 
SUMMARY OF THE INVENTION 
These and other disadvantages are overome, according to the present 
invention, by the provision of a balustrade unit comprising a pair of 
spaced-apart channel-section members, the mouths of which are directed 
towards each other, the free edges of each said channel-section member 
being bent so as to form a pair of longitudinally-extending flanges, and a 
pair of spaced-apart, longitudinally-extending engaging elements provided 
on and upstanding from the base portion of each said channel-section 
member; a plurality of balusters disposable between said channel-section 
members, each baluster having, adjacent each end thereof, a transverse 
slot, the two slots in each baluster being parallel and in register with 
each other and the ends of said balusters being receivable between said 
engaging elements when said balusters are in position between said 
channel-section members; and a plurality of spacers each one of which is 
extendable between adjacent balusters of said balustrade unit, each said 
spacer having a table portion the side edges of which are receivable in 
rebates in said longitudinally-extending flanges, and a pair of valances 
disposed normal to said table portion and adapted to irremovably engage 
with said engaging elements when said spacer is disposed between adjacent 
balusters, each said table portion including a bight the base of which is 
receivable in a said transverse slot and the limbs of which extend on 
either side of the baluster to enclose the space between baluster and 
longitudinally-extending flange. 
In one embodiment of the invention, one of the pair of channel-section 
members may be provided with an integral handrail portion located on that 
side of the channel-section member remote from the mouth thereof.

Throughout the specification similar integers are referenced by like 
numerals. 
In FIG. 1 is seen, in exploded view, a balustrade unit according to a first 
embodiment of the present invention, which unit has a pair of spaced-apart 
channel-section members, namely an upper member 1 and a lower member 2. 
Each channel-section member 1, 2 is preferably an extruded member of 
aluminium or aluminium alloy, as well may all the other integers or 
components of the present invention. As may be best seen in FIG. 3, 
channel-section members 1, 2 are interchangeable and each has a base 
portion 3 upon which are provided upstanding, longitudinally-extending 
engaging elements 4. The free edges of members 1, 2 are bent so as to form 
longitudinally-extending flanges 5. As will be seen, these engaging 
elements 4 have their free edges of hooked profile, the tip or point of 
the hook being disposed outwardly; inwardly, the profile preferably has a 
V-bead or the like along it, and the purpose of hook and bead will be made 
clear later herein. 
The balustrade unit includes a plurality of balusters 6, advantageously 
extruded members of square-section as shown in FIG. 6. However, such 
balusters as 6 could also be formed from timber or other suitable rigid 
materials if desired, although highly preferred are the square-sectioned 
balusters of, say 3/4".times.3/4" external dimensions ranging from 1.2 mm 
hollow core to solid square rod. Balusters 6 may be extrusions freely 
available from stock normally held by aluminium suppliers. Each baluster 6 
has transverse slots 7, one adjacent each end, and it will be appreciated 
that such may be economically fabricated from stock lengths of extrusion 
by what is known as a `supersaw` possessing three saw blades mounted 
side-by-side with a gap of pre-determined dimension therebetween. Thus, on 
a single pass of the saw, three cuts are made, the middle cut going right 
through the extrusion or rod and the two spaced side cuts producing top 
and bottom slots 7 respectively, so that while positioning the main, i.e. 
severing cut, with reference to the middle saw blade, the two sides are 
simultaneously formed, one being in that baluster which is next to be cut 
off and the other being the finishing slot in that baluster which has just 
been cut; thereby achieving a major saving in cost. This is contrary to 
many presently-known systems wherein a hole is formed in a section which 
is destined to accept a baluster, then the end of the baluster has a 
co-acting hole formed therein and then, after passing the baluster through 
the first mentioned hole, a holding cross-screw must be inserted. In the 
present invention, by contrast, all the forming operations are rapidly 
done at the time when the balusters are cut from the stock length, so that 
each one is the same as every other one simply because the spacing is 
easily made constant between the blades of the `supersaw`. 
The respective ends of each baluster 6 are received between engaging 
elements 4 of channel-section members 1 and 2, being a 
fractionally-oversized fit between the V-beads on the inner sides of the 
engaging elements 4, thus forcing them outwards a trifle for a reason to 
be later explained herein. 
The balustrade unit has a plurality of spacers 8, each one of which is 
configured to extend between adjacent balusters 6. Each spacer 6 includes 
a table portion 9, valances 10, and a bight having a base 11 and limbs 12. 
Table portion 9 of spacer 6 is of a width to fit between flanges 5 of 
channel-section members 1 and 2, the side edges being received in the 
longitudinally-extending rebates 13 in channel-section members 1,2 and the 
valances fitting either side of engaging elements 4. These valances 10 
have hooked profiles but in this case the tip or point of the hook is 
directed inwardly to co-act with the hooked profiles on engaging elements 
4, thus producing a positive `snap-fit` which cannot be disengaged without 
loss of integrity. The engaging elements 4, having been forced slightly 
outwards by the insertion therebetween of a baluster 6, are now forced 
inwards by valances 10 hard against the baluster. Spacer 8 is then pushed 
into contact with baluster 6 so that base 11 of the bight of spacer 8 is 
accommodated within transverse slot 7 and the limbs 12 extend on either 
side to enclose the spaces between baluster 6 and flanges 5. Thus the 
greater the force tending to pull the baluster out of the channel-section 
member the more firmly the valances tend to close. In this manner a 
straight shear loading is imparted to the valances and engaging elements 
and the assembly tends to behave as a solid or unitary structure which is 
completely rattle-free, even when located in a windy locality. This system 
also permits the use of hollow box-section balusters 6 which would 
otherwise be very difficult to connect to any kind of cross-members 
without providing the balusters with screw-flutes which reduce the 
strength and add to the weight of an otherwise ideal section. The absence 
of screw-fastenings also renders units according to the invention useful 
in "do-it-yourself" kit form because the top channel-section member 1 is 
not necessarily continuous. 
A further economy in cost may be effected because such spacers 8 may be 
initially extended in three-abreast format, that is to say, as a single 
section with very thin portions interspaced with the profiles, permitting 
the three discrete spacer extrusions to be knocked apart with a hammer or 
the like, or cut. These triple spacer components can be mated one with 
another, via the hooked valances, so that only their outer surfaces--their 
table portions and outwardly-oriented valances need be anodised. Thus 
instead of incurring a minimum cost of anodising a minimum perimeter of 
100 mm each, two triple-spacer sections mated hook-to-hook may be anodised 
in the full length so that the actual cost of anodising is reduced to that 
of twice the length of 102.7 mm plus the distance therebetween. This not 
only cuts anodising costs but provides six spacers per guillotining. 
Singly, such spacers are difficult to handle commercially but may be 
handled with much greater facility in the triple-spacer format. That is to 
say, they may be fed easily into a press which has three guillotine blades 
as well as, say, three bight-producing punches, thereby ensuring that the 
feeding into the press of a single length of extrusion causes the press to 
deliver three separate completed spacers per unit lengths of extruded 
strip. 
A further anti-rattle feature comprises a set of V-beads 14, best seen in 
FIG. 4, on the underside of table portion 9 of each spacer 8 which V-beads 
are slightly flattened on being received in the transverse slots 7, to 
thus wedge base 11 in slot 7. 
A newel post may be provided at each end of such a balustrade unit as has 
been described above. A suitable kind of newel post is to be seen in FIGS. 
1 and 7 particularly. Each newel post is composed of two mating half 
sections which irremovably engage with each other to form a said newel 
post. These two mating half-sections take the forms of a `female` 
half-section 15 and a `male` half-section 16. As has been previously 
described in relation to hooked-profile engaging elements which are a 
feature of valances 10 and engaging elements 4, the two half-sections 
`smap-fit` snugly together to thus constitute a newel post. Each newel 
post is securable to associated channel section members by conventional 
self-tapping screws which extend through appropriately-drilled holes in 
either one of half-sections 15,16 and on into registering screw-flutes in 
the channel-section members 1,2. Such screw-flutes are integral to the 
extruded profile and are referenced 17 in FIGS. 1 to 14 of the drawings. 
FIG. 2 illustrates a suitable post capping member comprising a plate 18 
having holes therein through which self-tapping screws pass into 
registering screw-flutes 19 in the male and female half-sections 16,15 of 
the newel post. However, more preferred is a simple cap of a suitable 
plastics material with spigots thereon to mate with the said screw-flutes. 
FIG. 7 shows a top channel-section member having an arcuate-topped integral 
handrail portion 20, apart from which the arrangement is just as 
previously described. 
FIGS. 8, 9, 10 and 11 illustrate a modification in which a separate 
handrail 21 is provided. In this embodiment the top channel-section member 
has longitudinally-extending flanges 22 which are bent first outwardly and 
then upwardly and the free edges of the upwardly-turned flange portions 
are equipped with hooked-profile engaging elements which engage with 
co-acting hooked-profile engaging elements provided on separate handrail 
21, as is best to be seen in FIG. 9. The lower channel-section member 2 is 
exactly as previously described in relation to FIG. 1. 
The mouth of each channel-section member, whether the interchangeable pair 
1,2 or the modified top channel-section members as shown in FIGS. 7 to 11, 
is of great advantage in that it will also accept a system of glazing 
strip members to permit the easy assembly of `push-up-drop-down` glazing 
panels. FIGS. 10, 11 and 12 illustrate this embodiment in some detail. 
Prior art systems do exist but are generally not applicable to an 
efficient four-sided glazing arrangement. However, such an arrangement is 
rendered possible in accordance with the present invention which employs 
glazing strips between which glazing panels, of glass or plastics 
material, are disposable. As is best to be seen in FIG. 10, there are 
provided glazing adaptor pieces 23 which are adapted to `snap-fit` onto 
newel posts 15,16 via beads 24 (see FIG. 10) which engage with grooves 25 
in the newel post half-sections. The horizontal glazing strips 26, 
preferably formed from PVC or the like, each have lips 27 between pairs of 
which a glazing panel 28 is receivable. Glazing strips 26 fit into the 
mouths of the top and bottom channel-section members and have 
outwardly-turned flanges 29 which effectively enclose the spaces between 
glazing panel 28 and the longitudinally-extending flanges of the top and 
bottom channel-section members. 
Vertical glazing strips are composed of two parts 30 and 31 which together 
provide a pair of lips between which the glazing panels 28 are receivable. 
Vertical glazing strips 30,31, again preferably formed from PVC or the 
like, are provided with a pair of `ears` 32 which snap-in to a re-entrant 
element 33 on glazing adaptor pieces 23. 
To assemble a glazed balustrade unit, horizontal glazing strips 26 are 
installed in the mouths of the top and bottom channel-section members and 
part 30 of the vertical glazing strips is engaged with glazing adaptor 
pieces 23, which are in turn engaged with a newel post half-section. 
Glazing panel 28 is then `push-up-drop-down` fitted between the lips of 
the horizontal glazing strips 26 and beds against part 30 of the vertical 
glazing strips. The co-acting push-on parts 31 are then applied without a 
bonding agent. The parts 31 do not bear any load but merely hold the 
vertical edges of the glazing panel to make a complete four-sided glazing 
seal. 
FIG. 13 shows a cross-section of a corner-post arrangement particularly 
suited to the embodiment illustrated in FIGS. 8 to 11. Such a corner-post 
34 is an extrusion of aluminium or aluminium alloy and is provided with 
two pairs of female, `snap-fit`, longitudinally-extending engaging 
elements 35 which engage, in a manner previously described, with 
co-operating male newel post half-sections 16. A suitable metal or 
plastics capping member covers the top of corner-post 34, which, to this 
end, is provided with screw-flutes 36. 
Finally, FIG. 14 illustrates a suitable fixing assembly for a newel post. A 
spigot 37, affixed to the structure upon which the balustrade unit is to 
be assembled, extends upwardly between the two half-sections 15,16 of a 
newel post. A complementary pair of cover pieces 38,39 is provided with 
male engaging-edges 40 and female engaging-edges 41 which snap together 
about newel post 15,16 and its centrally-located spigot 37 to hold the 
assembly in rattle-free engagement. 
From the foregoing, it will be appreciated that balustrade units made 
according to the present invention ensure considerable cost savings from 
the use of ultralight metal extruded members which have an eye appeal 
superior to previously-known balustrade units, and which not only weigh 
less but cost less for the finishing thereof because less anodising is 
necessary, as above described. Moreover, the use of hollow, uninterrupted 
sections as balusters ensures a great saving in fabrication cost and 
permits selection to be made from commercially available supplies.