US3736717A

US3736717A - Window and panel frame structure

Info

Publication number: US3736717A
Application number: US00155109A
Authority: US
Inventors: W Farley
Original assignee: Individual
Current assignee: Individual
Priority date: 1971-06-21
Filing date: 1971-06-21
Publication date: 1973-06-05
Anticipated expiration: 1990-06-05

Abstract

A frame structure for supporting window and panel materials, wherein the frame structure comprises a vertical mullion assembly and a horizontal transom assembly joined together to form various sized frame-supporting structures. Both the mullions and transoms are formed from elongated channel-like extrusions adapted to receive different sized windows and panels, particularly for construction of outer walls of buildings. The windows and panels alike are locked into place by a snap-in casing that is accommodated in both the mullions and transoms. The transom assembly is secured in and supported by the upright mullion assembly, which when assembled together form a box-like frame structure having the windows and panels supported therein.

Description

United States Patent [1.91

Farley 51 June 5, 1973 541 WINDOW AND PANEL FRAME STRUCTURE Primary ExaminerPrice C. Faw, Jr. [76] Inventor: Walter J. Farley, 2328 Montera Ammey FranclS xLojaconosr' Drive, Hacienda Heights, Calif. [57] ABSTRACT [22] filed: June 1971 A frame structure for supporting window and panel [2]] App]. No.: 155,109 materials, wherein the frame structure comprises a [52] US. Cl. ..52/476, 52/235, 52/498 Supporting Structures Both the mulhons and transoms [51] IIIILCI. ..E04b 2/88 are formed from elongated channeblike extrusions [58] Field of Search ..52/235, 241, 476, adapted to receive different sized windows and panels 52/495, 496, 498, 401, 502, 731, 732 particularly for construction of outer walls of buildings. The windows and panels alike are locked [56] References C'ted into place by a snap-in casing that is accommodated in UNITED STATES PATENTS both the mulhons and transoms. The transom assembly 18 secured in and supported by the upright 3,403,491 /1968 Eichmap. ..52/476 mullion assembly, which when assembled together 3,140,763 7/1964 E e n... form a box-like frame structure having the windows $053,353 9/1962 Mlllfil and panels upported [herein 3,081,849 3/1963 l-lubbard..... 3,147,518 9/1964 Horgan ..52/476 10 Claims, 10 Drawing Figures /Z I 28 m: #8 32 M0 8a I j 86 5 //2{ I /4; 80 76 78 l 4 is 42 Z2 52 68 v f 4 /02 I. 70 //z' 50 /0 5 Z6 56 54 w ma vertical mullion assembly and a horizontal transom assembly joined together to form various sized frame- BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates, generally, to window and panel frame structures and, more particularly, to frame structures formed of extruded channels.

2. Description of the Prior Art As is well known in the art, various problems and difficulties are encountered in providing suitable means for constructing large, substantially glass, outer walls of a building. The frame structure of such a wall at the present time is very costly due to the many intricate components that are required to satisfactorily support the weight of the structure involved. Because of the fact that the glass windows used in this type of construction are quite large in size, the problem of static wind pressure is to be considered. If the window panes are not properly set within the frame structure, high static wind pressure will cause the panes and panels to shift back and forth, causing damage to the seals and, thus, allowing wind and rain to enter therethrough.

SUMMARY OF THE INVENTION The present invention comprises a window and panel frame structure used as a curtain wall in the construction of large multi-floor buildings. The frame structure comprises a vertical mullion assembly and a horizontal transom assembly interlocked with each other to form a box-like frame structure to support the window and- /or panel, as required.

The mullion assembly comprises an elongated, extruded double-channel member adapted to receive the vertical edges of different sized window or panel thicknesses, which are held in place in the channels by a snap-in casing secured between the panel and one wall of the channel member. Various sized ribs are integrally formed along the channel walls and so designed as to permit the glass or solid panels to be easily installed but, yet, capable of securing the panels from shifting under adverse conditions.

The transom assembly, which is interlocked and supported in the upright mullion assembly and extends horizontally therefrom, is comprised of a single extruded member which is reversibly fitted to an identical extruded member to form an interlocked dual-channel support for receiving the upper and lower edges of the various panes or panels. To conform with the simplicity of construction, the upper and lower edges of the panels are also secured within the dual channels by use of the same snap-in casing that is provided in the mullion assembly.

The windows and panel sections are sealed within the channels by typical glass bead seals, which also serve as a frictional holding means along the edges thereof.

Secured within the double channels of the mullions and transversely positioned through the rib members of the channels are load-supporting pins, to provide a positive support for each transom assembly.

A second embodiment is included herein having the same mullions and transoms as described above, except that the glass panes and panels are positioned adjacent the opposite channel walls, wherein the normal outside walls of the frame structure are reversed and become the inner frame portion having one of the snap-in cas ings formed with a flat, inwardly-extending, shelf-like member provided at its outer end, with a depending channel to receive and support an inner wall panel.

OBJECTS AND ADVANTAGES OF THE INVENTION The present invention has for an important object a provision for supporting and securing window panes and/or panels of different sized thicknesses, without the requirement of special components or tools.

It is another object of the invention to provide a window and panel frame structure that requires only three major extruded components.

It is a further object of the invention to provide a window and panel frame structure that is capable of supporting large panes and/or panels, and also preventing shifting of said panes and/or panels within the frame structure under high static wind pressure.

A still further object of the invention is to provide a frame structure of this character that is relatively inexpensive to manufacture.

Another object of the invention is to provide a frame structure of this character having a mullion assembly with positive securing and supporting means for each horizontal transom assembly.

A further object of the invention is to provide a frame structure of this character comprising extruded mullion assemblies and transom assemblies that are simple and easy to assemble, service and maintain.

Still another object of the invention is to provide a structure of this character wherein the normal inside portion of the frameis capable of being reversed to the outside, and vice versa, for the normal outside portion of the frame.

Other characteristics, advantages and objects of this invention can be more readily appreciated from the following description and appended claims. When taken in conjunction with the accompanying drawings, this description forms a part of the specification wherein like references and characters designate corresponding parts in several views which are as follows:

DESCRIPTION OF THE DRAWINGS Referring more particularly to the accompanying drawings, which are for illustrative purposes only:

FIG. 1 is a partial elevational view of a curtain wall structure incorporating the present invention;

FIG. 2 is an enlarged cross-sectional view taken on line 2-2 of FIG. 1 thereof;

FIG. 3 is an enlarged cross-sectional view taken on line 3-3 of FIG. 1.

FIG. 4 is a transverse cross-sectional view of a mullion with the end of a transom member secured and supported therein;

FIG. 5 is a cross-sectional view taken on line 5-5 of FIG. 4;

FIG. 6 is a similar view to that of FIG. 5, but showing a different type of support means for the transom assembly;

FIG. 7 is a partial perspective view of the double channel extrusion member of the mullion assembly;

FIG. 8 is a partial perspective view of an extruded member which forms the transom assembly;

FIG. 9 is a partial perspective view of the snap-in cas; ing; and

FIG. 10 is a cross-sectional view similar to FIG. 3 showing an alternative embodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings and, more particularly, to FIG. ll, there is shown a portion of a curtain wall, generally indicated at 10, representing an outside wall of a multi-story building structure. Generally, the curtain wall comprises a frame structure 12, supporting window panes 14 and panel members 16, which are shown positioned between the upper and lower ends of said window panes 14.

The frame structure 12 includes a plurality of mullion assemblies, which are the vertical portions of the frame structure 12, and transom assemblies that are horizon tally positioned between each upright mullion structure, each assembly being indicated generally by reference numerals l8 and 20, respectively.

The mullion assemblies comprise an elongated, double channeled, extruded beam member 22 having a somewhat central web wall 24. One portion of the web wall 24 provides a partition 24a between

channels

26 and 28, respectively, as indicated in FIGS. 2 and 7. The other part of wall 24 extends outwardly, becoming an integral part of an outer wall 30, which is formed normal to said wall 24, forming a somewhat T-shaped configuration. In order to strengthen the structural area of the

walls

30 and 24, there are provided

flanges

32 and 34, inwardly bent along a parallel plane of the wall 24.

The extrusion in FIGS. 2 and 7 has the two

channels

26 and 28 extending in opposite directions and having a common channel bottom 24a, and

side walls

36 and 37 formed at right angles to the bottom 24a for receiving the edges of windows 14 in end-to-end relationship. Therefore, channel 26 is formed by a portion of

wall

36 and 37 as side walls thereof, and partition 24a providingthe bottom wall. Channel 28 is also formed by one portion of the

walls

36 and 37, and partition 24a.

Referring first to channel 26, there is provided in that portion of the wall 36 an integral inwardly-formed support rib 38 extending along the entire length of the channel and having an oppositely-disposed support rib 40 which is formed as an integral part of wall 37. These ribs are positioned adjacent and parallel to the bottom wall 24, forming oppositely-arranged

channels

42 and 44. There are provided in each inner face of

walls

36 and 37 sealing and mounting

grooves

46 and 48, respectively. Each of said grooves is positioned between the

ribs

38 and 40, and the

outer edges

50 and 52 of the

walls

36 and 37. The grooves are adapted to receive a sealing or packing means 54, generally comprised of an elongated neoprene bead. It should be noted that there are many kinds of seals and packings and any one might be used, depending on the particular construction requirements. When the window 14 is placed within the channel 26, it is positioned against the sealing means 54 on one side and is forced to remain in a sealed relation by being locked into place by a snap-in casing, indicated generally at 56. The casing 56 is provided with a somewhat flexible lip member 58 which is adapted to be received within channel 42, hooking behind rib 40 by means of shoulder 60, as seen in FIG. 2. This allows for a firm grip of the casing 56 when a flexible snap arm 62 is forced inwardly to engage mounting groove 46. The snap arm 62 extends inwardly from a flat wall 64 of the casing 56 along one side thereof and is provided with an outwardly-projecting tongue 66 which rests within the groove 46. Arm 62 extends inwardly and upwardly from tongue 66 so that the casing can be more readily received within the channel 26 and held in place by the tension between arm 62 and the opposite wall 68. Wall 68 is provided with a similar sealing groove 70 therein, to accommodate another sealing means 54 which is thereby forced against the inner face of the window 14. These sealing means 54 are additionally used to fixedly support the windows in their respec tive channels.

Channel 28 is somewhat similar in construction to that of channel 26. However, an additional pair of oppositely-disposed

ribs

72 and 74 are interposed between

smaller width ribs

76 and 78, respectively, and the bottom wall 24a. Said

ribs

72 and 74 are arranged parallel to

ribs

76 and 78 but extend inwardly from side walls 36 and 37 a distance greater than

ribs

76 and 78, thereby creating a very firm extension member capable of carrying weights heretofore not capable of being carried by other structures.

It should be understood that, when the frame structure 12 is constructed and the mullions are in place,

Channel 26 of one mullion will be oppositely opposed to channel 28 of the adjacent mullion so as to provide a proper clearance when fitting each window pane 14 or panel 16 therein. The fitting of each member, particularly a large window pane, is accomplished by inserting one of the vertical edges, such as indicated at 80, of the window 14 first into channel 28, then passed and between the

ribs

72 and 74, allowing room at the opposite edge to easily pass about the adjacent mullion extrusion, at which time both edges of the window are p0- sitioned within each

respective channel

26 and 28.

Channel 28 is also provided with sealing and mounting grooves 82 and 84, such as those in channel 26. The window 14 is locked into a fixed and sealed position along the outer portion of wall 37 of channel 28 by sealing bead 54 and held in place by snap-in casing 56, as previously described in relation to channel 26, with the exception, however, that

channels

42 and 44 are formed by

ribs

72 and 76, and 74 and 78, respectively.

As for weather protection and ornamental design, there are provided cover strips 86 and 88. Under normal construction the T-shaped portion of the extrusion is located on the outside of the building and exposed to weather and, therefore, would be covered by the somewhat U-shaped, thinly-extruded cover 86, made preferably of aluminum.

Along the outer free edges of the cover 86 there are formed protruding shoulders which, when forced over the projecting ribs 102 of the wall 37, snap into recess 104 along the outer face of each of said ribs 102. (See FIGS. 2 and 7) Cover 88 is snapped into position over the wall 36, which is generally located within the building structure. The cover comprises a substantially flat wall 106 having flanges 108 thatare capable of snapping into position by means of lips 110, formed along the outer free edges of the flanges 108, which are adapted to be received within elongated matching recesses 112.

Referring now to FIG. 3, there is a cross-sectional illustration of the extrusions which comprise the transom assembly 20 of the frame structure 12. The extrusions are generally indicated by reference numeral 114, as seen in FIG. 8, and have a configuration substantially that of a T laying on its side. In order to assemble a transom section, two identical pieces are cut from the a plurality of mullion assemblies vertically positioned and equally spaced in parallel relationship to each other within said frame structure;

a plurality of transom assemblies horizontally positioned between each of said mullion assemblies, said transom assemblies being spaced apart in a parallel predetermined distance;

a removable interlocking means between the outer free ends of said transom assemblies and said mullion assemblies; and

means for removably securing said window or panel members within said mullion and said transom assemblies, wherein each of said mullion assemblies comprises: an elongated mullion extrusion member having oppositely disposed dual channel members, each of said channels having the same bottom wall,

and at least one pair of parallel side walls extending therefrom,

said side wall being spaced apart with suitable clearance for said window or panel members, and securing means to be inserted therebetween,

said side walls being provided ontheir inner faces with sealing grooves and longitudinal ribs, wherein said free ends of said transom assemblies can be removably engaged therewith, and

means provided within said ribs for supporting said interlocking means; and wherein each of said transom assemblies comprises:

a first transom extrusion member;

a second transom extrusion member identical to said first extrusion member, both being reversibly fitted into each other;

oppositely-disposed dual channels formed by said reversibly-fitted extrusions, each channel having extending side walls suitably spaced apart to receive said securing means and said window or panel members therebetween, said walls being provided on their inner faces with integral longitudinal support ribs and sealing grooves.

2. A curtain wall, as recited in claim 1, wherein said means for removably securing said window or panel members within said mullion and said transom assemblies comprises:

a snap-in casing member adapted to be received in said channels of said mullions and transom assemblies.

3. A channel wall as recited in claim 2, wherein said snap-in casing member comprises:

a flat wall;

a depending side wall;

a sealing groove in said side wall; a lip member extending outwardly from said side wall and adapted to frictionally engage at least one of sais ribs within said channels of both assemblies; and

an arm member depending from the opposite side of a pair of corresponding notches provided within both ends of at least one of the transom extrusions, said notches being positioned to receive oppositely; disposed ribs therein.

5. A curtain wall, as recited in claim 3, wherein said removable interlocking means comprises:

an angle member removably mounted within each of said channels of said mullion extrusions for sup porting the free ends of said transom assemblies thereon; and

a pair of notches, each of which is provided within oppositely-disposed ribs of said channels of said mullion extrusions for supporting the free ends of said transom assemblies thereon; and

a pair of notches, each of which is provided within oppositely-disposed ribs of said mulltion extrusions for receiving and supporting said angle members.

6. A curtain wall, as recited in claim 5, including:

means for sealing said window and panel members within said channels of both of said mullion and transom assemblies, said sealing means being secured within said sealing grooves of said channels and said casing.

7. A curtain wall, as recited in claim 6, including:

cover walls for covering said mullion and transom assemblies;

means for removably securing said cover walls to said mullion and transom assemblies.

8. A curtain wall, as recited in claim 7, wherein the snap-in casing member secured in one of said channels of said transom assembly comprises:

a flat wall extending outwardly from said transom extrusion;

a depending side wall;

a sealing groove in said side wall;

a lip member extending outwardly from said side wall and adapted to frictionally engage at least one of said ribs within said channel of said transom assemy;

an arm member depending from said flat wall intermediate the depending wall and the opposite edge of said flat wall, and provided with an outwardlyextending shoulder for positive locking engagement with at least one of said grooves; and

a depending channel member formed along the longitudinal outer free edge of said flat wall.

9. A curtain wall, having a frame structure for supporting window and panel members, comprising:

a plurality of mullion assemblies vertically positioned and equally spaced in parallel relationship to each other within said frame structure;

means for removably securing said window or panel members within said mullion and said transom assemblies, a casing member extending outwardly from at least one of said transom assemblies, said casing member comprising:

a flat, horizontal wall extending outwardly from said transom member and removably secured thereto,

extrusion 114 and then reversibly fitted together, as shown in FIG. 3. Each member therein is referred to by

reference characters

116 and 118, respectively. Since each

member

116 and 118 is identical to extrusion 114, a description of extrusion 114 should suffice.

FIG. 8 clearly illustrates that extrusion 1 14 comprises a structural partition 120 integrally formed along each opposite edge of

walls

122 and 124. The junction of the partition with wall 122 is positioned closer to one outer edge of wall 122 than the opposite edge thereof. That is, the depending portion of wall 122, as seen in FIG. 8, is substantially shorter than that of the upper portion. This allows for an enlarged channel 126 to be formed by rib member 128 extending inwardly from said wall 122 and parallel to partition 120. A similar rib 130 extends inwardly from the lower portion of wall 122 and forms a channel 132 with the opposite side of partition 120, said channel 132 being smaller in width than channel 126. Sealing and mounting

grooves

134 and 136 are provided in the inner face of wall 122 along the outer parallel edges thereof.

Referring to FIG. 3, there is shown a cross-sectional view of an assembled transom 20, in which said assembly comprises a pair of

extrusions

116 and 118 being allochirally-arranged relative to each other. That is,

extrusions

116 and 118 are identical but oppositely arranged so that one forms a right hand extrusion and the other forms a left hand extrusion, whereby they can be interlocked to provide oppositely-disposed

channels

138 and 140.

The interlocking of the

extrusions

116 and 118 is accomplished when wall 124 of each extrusion is forcefitted into the corresponding enlarged channels 126.

The channel 138 faces upwardly from the transom assembly 20 in order to properly receive the lower edge of window 14, and said channel 140 faces downwardly therefrom to properly receive the upper edge of the panel 16.

The lower edge of said window 14 is secured between sealing

beads

142 and 144, respectively. The sealing bead 142 is held in place by being adapted to be received in groove 134 of extrusion 116, while the sealing bead 144 is received in groove 70 of the snap-in casing 56.

The casing 56 covering the upper channel 138 is locked into position when lips 58 and shoulder 60 are hooked between rib 128 of extrusion 116 and partition 120 of extrusion 118, and tongue 66 is engaged within groove 136 of extrusion 118.

In like manner, an additional casing 56 is snapped into place over the lower channel 140, securing panel 16 between sealing bead 146 and 148.

Both extrusions 1 16 and 1 18 are provided with shoulders 150 along the outer edges thereof for receiving lips 110 of cover plates 88, identical to those used in the mullion assembly 18.

The mullion assemblies 18 and transom assemblies 20 are interlocked by means of dowel pins 152, as seen in FIGS. 3, 4 and 5. Said pins are mounted within holes 154 which are axially and sequentially aligned to each other and transversely to said

channels

26 and 28 of extrusion beam 22. The pins 152 extend through the contiguous holes 154 so that each free end of the pins is adjacent the open sides of each

channel

26 and 28, thereby passing through

channels

42 and 44, respectively, and permitting the transom assembly to rest thereon when each free end of said transom assembly is positioned within

channels

26 and 28. One of the extrusions, such as extrusion 118, is provided with

notches

156 and 158, as shown in FIG. 4, so that the transom assembly can be slidably received in

channels

26 and 28 by allowing the

notches

156 and 158 to pass over

ribs

38 and 40. When this occurs, legs 160 and 162 which are formed by the

notches

156 and 158, respectively, are interposed within

channels

42 and 44, thereby holding each transom assembly 20 from any lateral movement and providing a positive connection and a stable frame structure with a minimum amount of components.

In FIG. 6, there is shown an alternative arrangement, whereby the free end of an extrusion 114 may be provided with a support means other than pins 152. This arrangement comprises an angle member 164 having a flat, upper support wall 166 extending outwardly from said

channels

26 and 28, and having a depending flange member 168. The flat wall 166 is removably supported within notches 170 of the

ribs

38, 40, 76 and 78.

ALTERNATIVE ARRANGEMENT Referring now to FIG. 10 in which ther is shown an alternative arrangement of the invention, it should be first understood that in this arrangement the normal outside area of the curtain wall 10, as previously described, is arranged to be inside the building structure, whereby the normal inner area is now reversed. To accomplish this arrangement, the window panes and panels are now positioned and secured in the opposite sides of the

channels

26, 28, 138 and 140, as hereinbefore described. Then the snap-in casing 56, located in channel 138, is replaced by a snap-in casing, generally indicated at 180, comprising a substantially inwardlyextending, upper flat wall 182, forming a shelf-like member having a depending flange member 184 adapted with a sealing groove 186 in which a typical sealing bead is received. Along the lower edge of the flange 184 there is provided a locking means similar to that used in snap-in casing'56. Positioned inwardly from flange 184 and depending downwardly from the flat wall 182 is a snap-in arm 188 for engagement with groove 136.

There is a depending channel member, indicated generally at 190, depending downwardly from the outer edge of the casing and extending longitudinally therewith to receive an inner partition or wall member 192.

When wall 192 is placed within channel receiving member 190, a dead space 194 is created between wall 192 and panel 16 in one direction, and from the level of the transom to the floor of the building in the other direction. This space 194 provides a means for locating hidden wires and pipes in the building.

The invention and its attendant advantages will be understood from the foregoing description and it will be apparent that various changes may be made in the form, construction and arrangement of the parts of the invention without departing from the spirit and scope thereof or sacrificing its material advantages, the arrangement hereinbefore described being merely by way of example, and I do not wish to be restricted to the specific form shownor uses mentioned, except as defined in the accompanying claims.

I claim:

1. A curtain wall, having a frame structure for supporting window and panel members, comprising:

9 10 means for removably securing said casing member 10. A curtain wall as recited in claim 9 wherein said to said transom assembly, and formed along one receiving member comprises a depending channel and longitudinal edge of said flat wall, and includes a partition member vertically supported and a receiving member disposed along the opposite, received in said channel.

longitudinal, outer free edge of said flat wall. 5

Claims

1. A curtain wall, having a frame structure for supporting window and panel members, comprising: a plurality of mullion assemblies vertically positioned and equally spaced in parallel relationship to each other within said frame structure; a plurality of transom assemblies horizontally positioned between each of said mullion assemblies, said transom assemblies being spaced apart in a parallel predetermined distance; a removable interlocking means between the outer free ends of said transom assemblies and said mullion assemblies; and means for removably securing said window or panel members within said mullion and said transom assemblies, wherein each of said mullion assemblies comprises: an elongated mullion extrusion member having oppositely disposed dual channel members, each of said channels having the same bottom wall, and at least one pair of parallel side walls extending therefrom, said side wall being spaced apart with suitable clearance for said window or panel members, and securing means to be inserted therebetween, said side walls being provided on their inner faces with sealing grooves and longitudinal ribs, wherein said free ends of said transom assemblies can be removably engaged therewith, and means provided within said ribs for supporting said interlocking means; and wherein each of said transom assemblies comprises: a first transom extrusion member; a second transom extrusion member identical to said first extrusion member, both being reversibly fitted into each other; oppositely-disposed dual channels formed by said reversiblyfitted extrusions, each channel having extending side walls suitably spaced apart to receive said securing means and said window or panel members therebetween, said walls being provided on their inner faces with integral longitudinal support ribs and sealing grooves.

2. A curtain wall, as recited in claim 1, wherein said means for removably securing said window or panel members within said mullion and said transom assemblies comprises: a snap-in casing member adapted to be received in said channels of said mullions and transom assemblies.

3. A channel wall as recited in claim 2, wherein said snap-in casing member comprises: a flat wall; a depending side wall; a sealing groove in said side wall; a lip member extending outwardly from said side wall and adapted to frictionally engage at least one of sais ribs within said channels of both assemblies; and an arm member depending from the opposite side of said flat wall and provided with an outwardly-extending shoulder for positive locking engagement with at least one of said grooves.

4. A curtain wall, as recited in claim 3, wherein said removable interlocking means comprises: a pair of support pins fixedly mounted within the channels of said mullion extrusions and extending outwardly from said bottom wall of said channeLs to support the free ends of said transom assemblies thereon; and a pair of corresponding notches provided within both ends of at least one of the transom extrusions, said notches being positioned to receive oppositely-disposed ribs therein.

5. A curtain wall, as recited in claim 3, wherein said removable interlocking means comprises: an angle member removably mounted within each of said channels of said mullion extrusions for supporting the free ends of said transom assemblies thereon; and a pair of notches, each of which is provided within oppositely-disposed ribs of said channels of said mullion extrusions for supporting the free ends of said transom assemblies thereon; and a pair of notches, each of which is provided within oppositely-disposed ribs of said mulltion extrusions for receiving and supporting said angle members.

6. A curtain wall, as recited in claim 5, including: means for sealing said window and panel members within said channels of both of said mullion and transom assemblies, said sealing means being secured within said sealing grooves of said channels and said casing.

7. A curtain wall, as recited in claim 6, including: cover walls for covering said mullion and transom assemblies; means for removably securing said cover walls to said mullion and transom assemblies.

8. A curtain wall, as recited in claim 7, wherein the snap-in casing member secured in one of said channels of said transom assembly comprises: a flat wall extending outwardly from said transom extrusion; a depending side wall; a sealing groove in said side wall; a lip member extending outwardly from said side wall and adapted to frictionally engage at least one of said ribs within said channel of said transom assembly; an arm member depending from said flat wall intermediate the depending wall and the opposite edge of said flat wall, and provided with an outwardly-extending shoulder for positive locking engagement with at least one of said grooves; and a depending channel member formed along the longitudinal outer free edge of said flat wall.

9. A curtain wall, having a frame structure for supporting window and panel members, comprising: a plurality of mullion assemblies vertically positioned and equally spaced in parallel relationship to each other within said frame structure; a plurality of transom assemblies horizontally positioned between each of said mullion assemblies, said transom assemblies being spaced apart in a parallel predetermined distance; a removable interlocking means between the outer free ends of said transom assemblies and said mullion assemblies; and means for removably securing said window or panel members within said mullion and said transom assemblies, a casing member extending outwardly from at least one of said transom assemblies, said casing member comprising: a flat, horizontal wall extending outwardly from said transom member and removably secured thereto, means for removably securing said casing member to said transom assembly, and formed along one longitudinal edge of said flat wall, and a receiving member disposed along the opposite, longitudinal, outer free edge of said flat wall.

10. A curtain wall as recited in claim 9 wherein said receiving member comprises a depending channel and includes a partition member vertically supported and received in said channel.