FIELD OF THE INVENTION
This invention relates to exterior wall systems inserted between two adjacent floors known as window wall, specifically an improvement on the performances of the wall systems by the application of Airloop Principle as described by Ting in U.S. Pat. Nos. 5,452,552 and 5,598,671. The structure disclosed in U.S. Pat. No. 5,452,552 is also known as an exposed frame Airloop curtain wall system and the structure disclosed in U.S. Pat. No. 5,598,671 is also known as a hidden frame Airloop curtain wall system.
BACKGROUND OF THE INVENTION
A window wall system which in general, spans from the top surface of a floor to the underside of the floor above or to the bottom edge of a spandrel masonry or concrete panel above. Most of the window wall systems in the market include four types of wall components, namely, (1) a bottom sealing and anchoring member, (2) a top sealing and anchoring member, (3) shop prefabricated panel units installed between the bottom and the top anchoring members, and (4) an exterior floor slab cover. The parameters for a successful window wall project include durable weather shield, durable structural safety, ability to adjust for construction tolerances of the wall anchoring surface, easiness of erection, and no need for exterior access or lifting equipment. Any improvement on these parameters would represent an advance in the window wall technology. In addition, the ability to maintain a curtain wall type of flush exterior appearance is highly desirable but rather difficult since the window wall must be supported on the floor while the water infiltrated into the wall panel joints must be drained to the exterior of the slab edge making it become necessary for the slab edge cover to be protruded from the face of the window wall. Through years of experiences, the major areas needing further improvement are described as follows:
- (1) Water-tightness Performance: All conventional window wall systems require perfect sealing property at some critical sealing locations to maintain water-tightness performance. Experience indicated that the durability of the perfect sealing property at the critical seal locations is grossly inadequate due to workmanship and material degradation problems as well as stress fatigue due to various structural movements.
- (2) The erected window wall is expected to be plumb and leveled at the design position. However, a ±¾″ (19 mm) variation in the finished floor level as well as the floor edge location are normally considered as acceptable in the building industry. In installing each piece of the top or the bottom anchoring member in a conventional window wall system, shims as required are used to adjust it to the design location. These anchoring members are continuous along the foot print of the window wall and they can be field cut to fit at a wall terminating end or at a wall corner, there is no need for the positioning adjustment in the left-to-right direction. Thus, before the anchoring screws can be applied, the anchoring member must be adjusted to both the true in-and-out position and the true up-and-down position by using shims as required. The application of an anchoring screw requires two steps, namely pre-drilling the screw hole using a driller and applying the screw using a screw gun. In both steps of the screw application, the anchoring member is very easy to slide on top of the shims causing it to be out of position and the shims are very easy to shift out of position, therefore, it is a very time consuming process to achieve the required quality result. In addition, the structural strength of the anchoring screw would be reduced with a high shim condition. Even though a reduced screw strength can be theoretically compensated by a reduced screw spacing at the high shim locations, it can't be shown on the drawing since the high shim locations can't be predefined and it is totally impractical to execute in the field without a pre-engineering calculation. It is most likely to compromise the structural integrity of the erected window wall. Even though the required screw spacing can be conservatively engineered with the assumption of highest shim condition, it would significantly increase the cost.
- (3) In a conventional window wall system, each panel has a male jamb member and a female jamb member. The panels are erected in a fixed direction by engaging the male jamb into the female jamb of the already installed panel or vise versa. Due to the directional erection requirement, project delays are commonly caused by inadequate coordination with other trades on the job.
- (4) In a conventional window wall system, the exterior floor slab edge cover and some exterior perimeter caulking lines are normally applied from outside after the panel erection. This exterior access requirement has a significant impact on the erection cost especially in a congested inner city location.
- (5) An exterior wall system known as a Hybrid System represents an attempt to utilize the advantage of a window wall system for being supported between two adjacent floors and the advantage of a curtain wall system for flush exterior wall surface appearance. Experiences indicated multiple difficulties with anchoring and construction tolerance problems due to the notched mullion with discrete anchoring locations.
Therefore there is need for an improved window wall system that overcomes the disadvantages of conventional wall systems.
SUMMARY OF THE INVENTION
To achieve these and other advantages and in order to overcome the disadvantages of the conventional systems in accordance with the purpose of the invention as embodied and broadly described herein, the present invention provides an airloop window wall system that does not require exterior access during construction.
- Several objectives of the present invention include the following items.
- 1. To provide a window wall system with durable water-tightness performance.
- 2. To provide a window wall system to tolerate high degree of building construction tolerance with easy tolerance adjustment and without impairing the structural integrity of the anchoring system.
- 3. To provide a window wall system to allow for non-directional erection method.
- 4. To provide a window wall system to allow the use of completely interior access erection method.
- 5. To provide a window wall system having a flush exterior surface appearance of a typical curtain wall.
These and other objectives of the present invention will become obvious to those of ordinary skill in the art after reading the following detailed description of preferred embodiments.
It is to be understood that both the foregoing general description and the following detailed description are exemplary, and are intended to provide further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. In the drawings,
FIG. 1 is a typical partial elevation view of a window wall system incorporating an embodiment of the present invention;
FIG. 2 is a partial cross-sectional view taken along line 2-2 of FIG. 1 showing a vertical cross-section of an embodiment of the present invention taken at the floor slab edge;
FIG. 2
a is an alternative detail of FIG. 2 showing a flush exterior wall surface of a curtain wall system;
FIG. 3 is a partial horizontal cross-sectional view taken along line 3-3 of FIG. 1 showing a vertical panel joint of an embodiment of the present invention; and
FIG. 4 is a partial vertical cross-sectional view taken along line 4-4 of FIG. 1 showing the cross-section at a horizontal stack member of an embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION
Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts.
In order to better explain the working principles of the invention, the following terminology will be used herein:
Window Wall Panel: one of a plurality of panels or panel assemblies having at least one building facing wall element secured and nominally sealed to a panel frame, typically a perimeter portion of the facing element is shop secured and sealed to segments of the panel frame;
Inner Airloop: an air space substantially forming a loop around and near the perimeter edges of the facing elements and generally within the panel frame; and
Outer Airloop: an air space substantially forming a loop around and outside of the panel frame.
For clarity the following list of numeral references of the elements illustrated in the Figures is provided:
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Subject
Elements
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Airloop window wall system
10
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shop assembled window wall panels
11a to 11d
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horizontal intermediate stack member
12
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insulated, dual glass segments
12a, 12b, 12c
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base anchor member
13
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masonry fastener
14
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ceiling anchor member
15
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masonry anchor
16
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base track member
17, 17a
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metal screw
18
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ceiling track member
19
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fasteners
20
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sill frame
21, 21a
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metal screws
22
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air seal
23
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head frame
24, 24a
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air seal
25
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base membrane
26, 26a
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slab edge panel
27
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panel jamb frame
28a, 28b
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vertical joint member
29
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air seal gasket
30
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water seal gasket
31
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rain deflecting gasket
32
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air space under base track member
33
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outer Airloop segments
34a, 34b, 34c
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inner Airloop segments
35a, 35b, 35c
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air space inside stack member
35d
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air holes
36a to 36d
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head retainer
37
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base perimeter caulking
38
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base trim
39
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ceiling perimeter caulking
40
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head trim
41
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stack member
42
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reveal joint
43
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structural male lip on 17a
44
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structural lip on 50
45
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reveal joint
46
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rain screen leg on 24a
47
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wipe gasket
48
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recessed outer flange on 17a
49
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recessed outer flange on 19a
50
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FIG. 1 illustrates an embodiment of the window wall system 10 comprising an assembly of multiple shop assembled window wall panels (e.g. panels 11a through 11d) that are installed between two adjacent floors near the floor slab edge. Although FIG. 1 shows an embodiment of a window wall system 10 in which the infill material of each window wall panel 11a through 11d is composed of insulated, fixed dual glass segments 12a and 12b as well as an operable window sash 12c, the window wall system can also comprise other solid materials as facing elements such as aluminum plate, stone, foam panel etc. or ventilating louver for A/C unit. Although the panels 11a through 11d shown are panels with exposed panel frames on all four sides, the panels can also have hidden panel frames on all four sides or any combinations of hidden and exposed panel frames. And although the panels 11a through 11d shown in FIG. 1 are generally square, substantially flat panel assemblies, other assembly shapes of panels may also be used. But however the individual panels are shaped, multiple panels must be joined together to cover the opening area between two adjacent floor slabs.
As shown, an optional horizontal intermediate stack member 12 in each panel separates the panel area into a top facing panel 12a or 12c and a bottom facing panel 12b. None or any number of horizontal intermediate stack members 12 can be used in any individual window wall panel. The stack member 12 can be oriented in the vertical or any inclined directions also.
FIG. 2 shows a typical fragmentary cross-section taken along line 2-2 as shown in FIG. 1. The details include base details above the floor slab, ceiling details below the floor slab, and an exterior slab edge cover details. The following explanations consider the same ceiling details on the same floor of the base details. The erection of the window wall system can be separated into two major categories, namely the non-panel erection and the panel erection. The non-panel erection consists of the following five erection steps. The three dimensional positions of the window wall are defined by the following non-panel erection steps. (1) Position the base anchor member 13 at the true in-and-out position along the foot print of the wall. Without any adjustment for the true up-and-down position, secure the base anchor member 13 to the floor surface following the contour of the slab surface using masonry fastener 14. This singular directional adjustment of member 13 with direct contacting surface on the floor is very easy to maintain the position of member 13 during the application of the fastener 14. Only small shim (not shown) is required occasionally to correct the tilting of member 13 in the in-and-out direction, therefore, the structural integrity of the masonry fastener 14 is ensured. Then, install the base membrane 26 to prevent the wetting of the slab edge and to act as the base drain flashing. Even though rigid metal base flashing can be used for 26, membrane material is preferred due to its ability to follow any irregular edge conditions of the floor slab. (2) Engage the base track 17 with the base anchor member 13 and adjust it to the true up-and-down position, then, secure the base track 17 in position using the metal screws 18. It can be seen that this singular positioning adjustment of the base track 17 can be done very easily due to the tight engagement with the base anchor member 13. (3) Secure the ceiling anchor member 15 along the window wall line to the underside of the floor slab surface following the contour of the slab surface using masonry fastener 16. Similar to the above discussions, the structural integrity of the masonry fastener 16 is ensured. (4) Engage the ceiling track 19 to the ceiling anchor member 15 and adjust it to the true up-and-down position, then, secure to member 15 using metal screws 20. It can be seen that this singular positioning adjustment of the ceiling track 19 can be done very easily due to the tight engagement with the ceiling anchor member 15. Once the base track 17 and the ceiling track 19 are installed, the theoretical window wall positions in all directions (vertical, in-and-out, left-to-right) are defined. Combining the explanations of the above four steps, the floor slab construction tolerance can be easily adjusted without impairing the structural integrity of the anchoring fastener, The Objective No. 2 of the invention is achieved. (5) Install the decorative slab edge panels 27. The above five steps constitute the non-panel erection. Upon the completion of the panel erection, as shown, a typical panel sill frame 21 with a fixed glass 12b is structurally engaged with the base track 17 and secured in position by fastener 22 and air seal 23 is provided in between. Also as shown, a typical panel head frame 24 with an operable window sash 12c is caused to have structural contact with the ceiling track 19 and air seal 25 is provided in between.
FIG. 2
a shows alternative details of FIG. 2 with flush exterior wall surface over the slab edge area. To make this design possible, the exterior wall line must be protruded outwardly beyond the slab edge for a distance to allow adequate room for construction tolerance adjustment and the depth of the slab edge cover panel. To fulfill the above requirement, the exterior face of the base anchor member 13a and the ceiling anchor member 15a must be significantly off-set inwardly from the exterior wall line such that the base anchor member and the ceiling anchor member can maintain a firm contact with the slab top and bottom surfaces respectively as shown. The base track 17a has a recessed outer flange 49 to create a reveal joint 43 between the slab edge cover panel 27a and the sill frame 21a of the panel unit above. A structural male lip 44 is provided at the bottom of the outer flange 49 to cause engagement with the slab edge cover panel 27a. Similarly, the ceiling track 19a has a recessed outer flange 50 to create a reveal joint 46 between the slab edge cover panel 27a and the head frame 24a of the panel unit below. A structural male lip 45 is provided at the bottom of the outer flange 50 to cause engagement with the slab edge cover panel 27a. As shown, upon the engagement of the slab edge cover panel, 27a, a flush exterior wall surface is achieved. The Objective No. 5 of the current invention is achieved. By adjusting the depth of base/ceiling track members 17a, 19a and/or the depth of the slab edge cover panel 27a, either a protruding or recessed slab edge cover can be accomplished by this design. In conjunction with this design, a recessed rain screen leg, 47 and a wipe gasket 48 on top of 47 are provided in the head frame 24a. It can be seen that the water draining down between the membrane 26a and the unsealed cover panel 27a will be directed to the outside in front of the rain screen leg 47, therefore, effective water drainage is accomplished on each individual floor. In case of a steel frame building with spandrel beam near the slab edge, a slab edge extension under the floor slab can be installed to cover the depth of the spandrel beam and the same design can be used by simply considering the combined depth of the floor slab and the slab edge extension as the depth of the slab edge for the design of the slab edge cover panel.
FIG. 3 shows a typical fragmentary cross-section of a panel vertical joint of this invention taken along line 3-3 of FIG. 1. The right jamb frame 28a of the panel 11c (shown on FIG. 1) and the left jamb frame 28b of the panel 11d are joined by an independent vertical joint member 29 and air seal gaskets 30, water seal gaskets 31, and rain deflecting gaskets 32 are provided to seal the joint.
Reviewing FIGS. 1 to 3 simultaneously, the implementation of Airloop Principle is explained as follows. Each panel consists of a sill frame 21, a head frame 24 and two jamb frames 28a and 28b. The frame corners are miter-matched such that the air spaces 35a, 35b, and 35c are inter-connected to form the Inner Airloop. The air spaces 34a, 34b, and 34c are inter-connected to form the Outer Airloop. The air space 33 is subjected to the exterior air pressure. The Outer Airloop consisting of 34a, 34b, and 34c is pressure equalized to the air space 33 through air holes 36a. The Inner Airloop consisting of 35a, 35b, and 35c is pressure equalized to the Outer Airloop through air holes 36b. The pressure equalized Inner and Outer Airloops are formed to achieve durable water-tightness performance as explained in the cited Ting Patents. The Objective No. 1 of this invention is achieved.
Reviewing FIGS. 1 to 3 simultaneously, the panel erection is explained in the following steps by standing on the floor from the interior side: (1) Engage the vertical joint member into the jamb of the panel already secured in position; (2) Tilt the top of the panel to be erected inwardly and slightly away from the vertical joint member 29 and drop the panel into bottom engagement with the base track 17 and due to the dead weight moment, the top of the panel will automatically swing outwardly to cause contact with the ceiling track 19; (3) Slide the panel laterally to cause panel jamb engagement with the vertical joint member 29. As shown, there is room for adjusting the joint gap to take care of panel dimensional tolerance; (4) After multiple panels have been secured in position, drop in the head retainer 37 to provide structural support against positive wind load and snap in the spaced apart clips 38 to prevent the rotation of the head retainer 37; (5) Apply the base perimeter caulking 38 and snap on the base trim 39; (6) Apply the ceiling perimeter caulking 40 and snap on the head trim 41. Due to the use of independent vertical joint member 29 in combination of joint width adjustability, the panels can be erected from either from left-to-right or right-to-left and there is no problem for the process of leave-out-and-back-fill (i.e. non-directional erection method). Thus, the Objective No. 3 of this invention is achieved. The non-panel erection steps explained previously and the panel erection steps explained herein can all be easily done without exterior access, therefore, the Objective No. 4 of this invention is achieved.
FIG. 4 shows a typical fragmentary cross-section of an optional horizontal panel stack member 42 of this invention taken along line 4-4 of FIG. 1. As shown, the stack member 42 supports the operable window sash 12c on the top and a fixed glass at the bottom. The stack member 42 is fastened at the ends to the jamb frames 28a and 28b of the same panel. However, the ends of 42 are not completely sealed to 28a and 28b to allow the air space 35d to be connected to air space 35b to pressure equalize the air space 35d. The additional air holes 36c and 36d will serve to drain any water sipped into the air space 35d.
It is preferable to use extrudable materials for making the panel frame and perimeter frame members such as aluminum or PVC. At the sealing locations where relative displacement between the sealing components is expected, a contact type of sealant material such as gasket or foamed sealing tape is preferred.
Although preferred embodiments of the invention have been described in detail herein and illustrated in the accompanying drawings, it is to be understood that the invention is not limited to these precise embodiments and that various changes and modifications may be effected therein without departing from the scope or spirit of the invention.
Patent Grant
8001738
