Static structures (e.g. – buildings) – Sheetlike element assembled parallel to existing wall,...
Reexamination Certificate
1998-09-09
2001-03-27
Friedman, Carl D. (Department: 3635)
Static structures (e.g., buildings)
Sheetlike element assembled parallel to existing wall,...
C052S506050, C052S506080, C052S235000, C052S596000, C052S302300
Reexamination Certificate
active
06205731
ABSTRACT:
BACKGROUND OF THE INVENTION
The invention concerns a curtain-wall façade structure and a façade slab for a façade structure of this type. The invention also concerns a extrusion press tool for manufacturing a façade slab of this type.
A façade with façade slabs according to the main concept of claim
1
is known from DE-PS 34 01 271. These façade slabs consist of flat front and rear slab segments that are connected by stud links. Additionally, the back face of the slabs has a head and a foot lap that when the slab is mounted are positioned one beneath the other. Furthermore, the front lower edge of the façade slabs has a drainage lap that when the slab is mounted fits over the head lap of the slab below it in such manner that the front surfaces of the upper and lower façade slabs lie flat on one plane. The head lap of the lower façade slabs and the slab holders of the drainage lap or top façade slabs are covered in such manner that the holders are only partially visible. Between the foot lap of the upper façade slab and the head lap of the lower façade slab there is an open horizontal groove for ventilation of the façade. The façade slabs described are marketed in mill-finished, polished, and sandblasted surfaces.
Additionally, curtain-wall façade slabs are known that are less strong and are designed without perforations and without head, foot, and drain laps. These slabs are joined with open horizontal grooves of various widths. These façade slabs also are offered in mill-finished, polished, and sandblasted versions, and also in the form of decorative slabs with specific incised decoration.
In curtain-wall façades that are ventilated from behind, the grooves must be sufficiently open to permit a change of air to carry away the moisture diffused through the building wall. Through the pulsating effect of the wind, there is adequate ventilation through the open grooves of the façade slabs, which are overlapped like scales or abut one another on one plane. In rainy weather, particularly in the case of a driving rain, the water runs down the front of the façade slabs. Through the scale-like overlapping of façade slabs or the design of the overlapping head and drain laps the water drainage is improved in such manner that practically no driving rain can penetrate behind the façade slabs, yet ventilation and consequent exchange of moisture through the open horizontal grooves is not impeded.
The disadvantage of these known façade structures is that in the upper region of buildings, that is, near the roof edge, a strong wind can drive rainwater through the open horizontal grooves. The wind striking the building façade frontally collects on the façade and flows along both sides to the left and to the right and also upward near the top of the façade. In the case of tall buildings, particularly when the wind is strong, updriving wind velocities of such power can be reached in the upper reaches of the façade that the façade water stops flowing downward and is instead driven upward by the wind and, despite the overlapping of head and foot laps, is driven in large quantities through the open horizontal grooves behind the curtain-wall façade.
In the perforated slab according to DE-PS 24 01 271 there is a further disadvantage in that on the front surface, which during drying of plastic ceramic blanks is positioned at the top, in the area of the T-shaped cross-section formed by the front slab segment and the stud links, there is an accumulation of material that causes the formation, not only during drying, of shrinkage movements that take the form of optically unaesthetic flat depressions. In materials that are very sensitive to dryness the strong shrinkage movements can even lead to cracks.
DE-OS 25 01 323 discloses façade slabs for cladding building exteriors, which said slabs have recesses to give them the appearance of a brick or stone wall.
US-PS 52 13 870 discloses cladding slabs that have ornamental recesses.
US-PS 42 88 956 discloses cladding slabs made of rigid expanded polyurethane with recesses to hold attachment components.
Façade slabs having the cross-section shown in
FIG. 5
have also become known. These façade slabs have a front slab segment
41
and a back slab segment
42
connected by link studs
43
,
44
,
45
, forming core holes
46
,
47
between them. The front face of the front slab segment
41
has horizontal grooves
48
,
49
,
50
. The back face
51
of front slab segment
41
follows essentially the contour of the front face of front slab segment
41
, so that this front slab segment has essentially the same wall thickness
a
throughout. Accordingly, near grooves
48
,
49
,
50
in front slab segment
41
there are joggles
52
,
53
,
54
,
55
,
56
,
57
, the result being that core holes
46
,
47
are no longer rectangular compared to the original form without grooves
48
,
49
,
50
; rather, they have indentations that correspond to joggles
52
-
57
.
SUMMARY OF THE INVENTION
The task of the invention is to propose a façade slab of the type initially described that at least diminishes or even completely prevents the entry of rainwater when the wind is strong.
According to the invention, this task is accomplished by providing horizontal grooves on the front face of the front slab segment. Through the positioning of horizontal grooves the laminar layer of water flowing across the façade surface is broken and the flow resistance of the water is increased. The consequence thereof is that when the wind is strong less water is driven upward near the top of a façade, or the wind velocities at which the water begins to flow upward must be much higher than is the case with façades without grooves. Accordingly, less water is driven, or water is seldom driven, through the open horizontal grooves into the curtain-wall façade structure. Particularly in windy and rainy regions the moisture admission of the heat insulation and the building wall is considerably diminished. A further advantage is that the downward-flowing façade water flows slower and therefore after trickling down the window lintels strikes the windowsills with less speed, is less dispersed, and contributes less to the dirtying of the windowpanes.
A further advantage achieved by the invention is that quality defects in production are prevented, particularly if the façade slabs are manufactured by the extrusion press method.
Advantageous embodiments of the invention are described herein in the detailed description herein.
The disadvantage of the known façade slab shown in
FIG. 5
is that the front slab segment
41
must be joggled, which is possible only through use of an appropriately designed extrusion press nozzle with appropriate cores, with corresponding recesses at their front corners. The disadvantages of such a nozzle are that the nozzle frame must be equipped with recesses that correspond to the grooves, and that therefore this nozzle cannot be used for the manufacturing of façade slabs without grooves. In addition, all cores on the corners that face the front wall must be equipped with appropriate recesses, which involves special processes that can be used only in nozzles for façades with grooves and even, strictly speaking, with grooves having a specific cross-section. Since nozzle cores must be extremely wear-resistant, and as a rule are made of hard steel or carbide metal or are cast as oxide ceramic, cores with special forms are correspondingly expensive. If normal cores, that is, corners without recesses at the corners, were used, the thickness of the front of the façade slab would be reduced to a portion of the necessary thickness. This is shown by the broken line in
FIG. 5
, bottom left. In contrast, if cores with corner recesses were used in normal nozzles (for slabs without grooves), the wall would become thicker in the junction area (front wall/stud link), and because of a surplus material accumulation cracks would therefore form during the drying that is necessary during the technological manufacturing process.
A further disadvantage of such a nozzle with joggled walls is that these
Dilworth & Barese, LLP
Friedman Carl D.
Gerhaher Franz
Thissell Jennifer I.
LandOfFree
Front panel positioned in front of a facing construction does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Front panel positioned in front of a facing construction, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Front panel positioned in front of a facing construction will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2480541