Abstract:
A header of general U-shaped construction having a web and depending flanges normal to the web and separated by the web, and a stud, one end of which is interfitted between the flanges perpendicular to the web. The improvement comprising vertical slots formed in the flanges through which screws are passed uniting the header to the stud whereby the stud may move vertically with respect to the stud in response to environmental forces but not horizontally.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a building construction assembly and, more particularly, to a header for allowing horizontal, non-load bearing headers to vertically fluctuate in relationship to vertical, non-load bearing wall studs to which the headers are attached. By allowing the header freedom of vertical movement, the walls that are fixed to the vertical studs are protected from cracking because the freedom of vertical movement of the header prevents translation of mechanical stresses to the walls caused by downward, environmental forces on the header. 
     2. Background Information 
     Prior to the present invention, vertical studs were secured to horizontal headers that secured all the studs in a wall together. The walls, frequently made out of wall board or plaster board, were secured to both the vertical studs and horizontal headers. Joists were usually secured to the top of the header at right angles to the vertical studs and at right angles to the horizontal header. The joists would then extend between the headers. The floor or roof would be secured to the top of the joists. This meant that the floor or roof was rigidly secured to the header which was rigidly secured to the studs. As a consequence, any downward environmental pressures on the floor or roof were translated directly into downward pressure on the the header. This would cause the studs to bow and would also result in the headers applying downward pressure on the wall directly. As a result, the environmental forces applied to the floor or ceiling would be translated into mechanical stress on the walls, which would result in cracks in the walls. The cracks would be further aggravated when the environmental pressure on the floor or ceiling was alleviated because the cracks would expand when the stress was relieved. 
     Examples of environmental stresses that cause the above kinds of problems are numerous. One of the most common examples involves the weight placed on the headers from the floors above. As a multi-story building is constructed, additional weight is placed on the headers of the lower floors as additional floors are added to the building. The present invention provides a means for the lower floors to absorb the additional stress. 
     Environmental stresses external to the building itself are also effectively managed by the present invention. For instance, in those parts of the country where it snows, the accummulation of snow fall on the roof can be a source of environmental pressure that will cause the cracking problem in the walls described above. In desert regions of the country, it is common for non-load bearing walls to be made out of metal studs and headers because of the shortage of readily available sources of lumber. In such hot regions of the country, the high temperatures cause the metal to expand. As a result, the wall board attached to the studs and headers is pulled with the expansion causing the walls to crack. The cooling of the metal studs and headers during the cool desert nights and re-expansion during the day aggravates the problem. 
     Earthquakes are another example of a source of environmental stress that can be managed by the present invention. Building construction technologies for surviving earthquakes are founded on the principle that the building should move with the earthquake. Rigid structures are more likely to suffer damage during an earthquake. The present invention helps prevent cracks in walls caused by earthquakes by permitting the nonload bearing frame to move with the earthquake. Obviously, the invention will not be very effective during a major quake. But for structures situated in earthquake zones that suffer frequent minor quakes, the invention can be of assistance in preventing cracks in the walls. 
     In addition, those parts of the country that are subject to severe tropical and sub-tropical weather systems, such as those states along the gulf coast, are subject to wide fluctuations in barometric pressure. In the extreme situation in the case of a hurricane, the difference between the barometric pressure on the inside of a house and the atmospheric pressure outside can become so great that the house will actually explode. While the present invention would be of little use in that extreme situation, it would help prevent cracking of the walls during less severe weather conditions that involve substantial fluctuations in barometric pressure. 
     Furthermore, the environmental pressures on the floors of public buildings can be substantial. For example, the floors of office buildings must support substantial additional weight during office hours as a result of the increased foot traffic. The present invention can accommodate the additional traffic during the day and flex back to its original position when the human load is absent. The prior art would have transferred such fluctuations in environmental pressures to the walls, which would have caused cracks over time. Moreover, the present invention can accommodate increased loads caused by the addition of office furniture and equipment, which the prior art could not without causing strain on and cracking of the walls. 
     SUMMARY OF THE INVENTION 
     It is the purpose of the present invention to provide a horizontal header with vertical slots with means for securing the header to vertical studs by way of the slots whereby said header can rise and fall in response to environmental forces applied to the the floor or roof. 
     Another object of the present invention is to provide a sufficient number of vertical slots spaced at predetermined distances from each other along the header so that studs can be secured to the header at the desired distances from each other depending upon the needs of the particular situation. 
     Another object of the present invention is to provide vertical slots in a header that permit vertical movement of the header while preventing horizontal movement. 
     Still another object of the present invention is to provide a means for securing the horizontal header to the vertical stud through the vertical slot in the header in such a way so that the securement means does not prevent vertical movement of the header. 
     These and other objects and advantages of the present invention will become apparent from the following detailed description of the preferred embodiment of the invention without intending to limit the scope of the invention which is set forth in the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The advantages of the invention can be more clearly understood by reference to the drawings in which: 
         FIG. 1  is a perspective view of a vertically slotted header secured to a vertical stud by means of a screw; 
         FIG. 2  is an exploded perspective view of  FIG. 1 ; 
         FIG. 3  is a side elevational view of vertically slotted header secured to a vertical stud by means of a screw; 
         FIG. 4  is a side elevational view of the invention showing the highest, lowest and intermediate position of the header relative to the slot; and 
         FIG. 5  is an axial view of molding attached to a ceiling to conceal the space above the wall required by the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       FIG. 1  illustrates a building construction assembly generally designated  8 . The invention includes a header  10  of generally U shaped construction and a stud  12  also of generally U shaped construction. Preferably, the header  10  and stud  12  are of metal construction as described in U.S. Pat. No. 4,235,054. While the header  10  and stud  12  are depicted as being U-shaped, it will be apparent that the invention is not limited by the shape of the header and stud. Said header  10  and said stud  12  are generally positioned perpendicular to each other with said header  10  in the horizontal position and said stud  12  in the vertical position. 
     Said header  10 .is composed of a web  14  and depending flanges  16  that are bent normal to the plane of the web  14 . Said flanges  16  are spaced apart the width of the web  14 . Said header  10  is usually longer than it is wide. The flanges  16  of the header  10  are formed with slots  24  cut there through. The slots  24  are perpendicular to the longitudinal axis  26  of the header  10  and are vertically elongated. See FIG.  1 . 
     In the preferred embodiment, the slots  24  are a-proximately 1.25 inches in length and 3/16 inches wide. The slots  24  each include a pair of generally parallel spaced apart sides  23  and  25 . The slots terminate in a lower end  41  and an upper end  42 . The lower end  41  and upper end  42  may be accurate to better accommodate attachment means  20  when the header  10  is in its maximum upperward position  50  and maximum downward position  44 . See FIG.  4 . 
     The width of the stud  12  is less than the distance between the flanges  16  so that the stud  12  can fit between the flanges  16 . The slots  24  in the flanges  16  should be aligned so that each slot  24  in one flange  16  is in alignment with a slot on the opposite flange. 
     The preferred method for assembling the invention involves placing end  40  of stud  12  between flanges  16  so that the end  40  abuts against the bottom  30  of the web  14  such that the header  10  and the stud  12  are perpendicular to each other and a vertical slot  24  is generally centered on side  52  of the stud  12 . Appropriate attachment means, such as a self-tapping screw  20 , is positioned in the slot  24  midway between the bottom  41  of the slot  24  and the top  42  of the slot  24 . Once positioned, the self-tapping screw  20  is drilled into the stud  12 . 
     In another method of assembling the invention, holes  22  are pre-drilled in the stud  12 . The stud  12  is then inserted between said flanges  16  so that the holes  22  in said stud are aligned with the slots  24 . The attachment means  20  passes through the slot  24  and, through the hole  22  in the stud  12 . Said attachment means  20  is tightened down sufficiently to keep said header  10  and said stud  12  united, but not so tight as to prevent said header  10  from moving vertically in response to environmental forces as shown in  FIGS. 3 and 4 . This limitation with respect to the tension of the attachment means applies to all embodiments discussed herein. 
     The holes  22  in said stud  12  are positioned so that when the header  10  is forced downward to its maximum downward position  44  such that the top  42  of the slot  24  is abutted against said attachment means  20 , then the top  40  of the stud  12  will contact the bottom  38  of the web  14  of the header  10 . If the holes  22  in said stud  12  are positioned too close to the top  40  of the stud  12 , then the attachment means will are the full force of any downward pressure on said header  10 . This may shorten the lift expectancy of the invention. 
     If the holes  22  in said stud  12  are positioned too far from the top  40  of the stud  12 , then the bottom  38  of the web  14  will abut against the top  40  of the stud  12  before the header  10  has reached tits maximum upward position  50  in the slot  24 . In that case, the full vertical range of motion the invention is not being fully utilized. 
     In order to complete the structure, wall construction material, such as wall board  32 , is affixed to the studs in a conventional matter such as by wall board screws  30 . It is critical that the wall  32  is attached to the studs  12  and not the header  10 , which was done in the prior art. Otherwise, the movement of the header  12  would stress the walls  32 , which would defeat the purpose of the invention. It is also important that the walls  32  stop short of the header  12  so that space  28  remains between the top  46  of the wall  32  and the bottom  48  of the flange  16  of the header  12 . For aesthetic purposes, molding  56  may extend from the ceiling  58  to cover the space  28  above the top  46  of he wall  32 . 
     The invention and its attendant advantages will be understood from the foregoing description and it swill be apparent that various changes may be made without departing from the spirit of the invention.