Patent Publication Number: US-6981301-B2

Title: Device for installing a pre-hung door

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   This invention relates in general to installing pre-hung doors and more particularly, to a device that properly aligns and shapes a pre-hung doorframe during installation within a rough opening in a wall. 
   2. Description of the Related Art 
   In building construction, in which doors are to be installed, the building contractors leave rough openings in the walls where finish carpenters, according to the architectural plans for the building, will later install the doorframes and doors. Doorframes generally consist of a head jamb spanning the distance between two side jambs and must be installed so that the jambs are completely plumb, or vertical, the head jamb is horizontal, the entire frame is square, and all parts of the frame are in the same plane. The jambs are secured in place with nails or screws to studs forming the rough opening in the wall. Once the frame is secured to the rough opening, a door or set of doors are then attached to the frame. However, the frame material is relatively thin and the four corners, where the rectangularly arranged sections meet and are attached to each other, do not present a great deal of surface area for bonding. Therefore, the frame is prone to twisting, warping, bending, and separating during the installation stage. If the frame is not completely square, the door will not swing true and will not close properly. This can result in gaps between the door and the frame, the doors hitting the frame or floor, or not closing properly. 
   Pre-hung doors are well known by those in the art. Pre-hung doors are factory-manufactured doors, which include a door attached by hinges to a preassembled jamb. One technique of installing the pre-hung door and frame in a proper alignment is to place the door in the rough opening, which will be larger than the frame, center it in the frame, use a level on the jambs to ensure proper alignment, place shims between the jambs and the studs to properly space each end of the jamb from the studs to achieve vertical or horizontal alignment, and then screw or nail the frame to the shims and, in turn, the shims to the studs. This method is difficult and time consuming even for a skilled carpenter. To achieve any level of efficiency, this method requires two carpenters, one to hold the level and the jamb and the other to install the shims and screw the frame to the studs. Additionally, this method does not ensure that the frame is installed in a single plane. 
   Several prior-art devices have been introduced to improve upon the above-described process. One such device is Tuthill (U.S. Pat. Pub. No. 2004/0000061 A1), which discloses an apparatus for installing a frame and related appurtenances incorporating four corner members slidably and releasably joined with height and width adjusters. The Tuthill apparatus is placed within a preassembled doorframe and then placed within a rough opening in a wall. The apparatus keeps the frame square while it is shimmed and secured to the wall. The Tuthill apparatus, however, suffers from the disadvantage of only securing the frame to the apparatus in one direction with a frame member 110, allowing a section of the frame to slide out of skew during installation. Additionally, the floor of the building may not be perfectly level, however, the door must be. Therefore, the height from the floor to each side of the bottom of the frame will need to be set before securing the frame in the rough opening. The distance from the floor to the apparatus in Tuthill is constant and is set by the dimension of a strike side base frame section 144. If the floor is not level, the frame tilt will follow the floor. 
   Finally, the Tuthill apparatus has a horizontal adjustable brace 270. The presence of the brace prevents a worker from passing through the doorway opening during the installation process. This presents a difficulty to the carpenter who may need to work from both sides of the doorway to install the frame. It also prevents other workers from being able to pass through the opening while the device is in place, possibly slowing progress on other areas of the building. Other prior art doorframe-hanging devices that suffer from this same disadvantage are: Washington (U.S. Pat. No. 773,176), Durkee (U.S. Pat. No. 1,257,2000), Hansen Jr. (U.S. Pat. No. 1,627,175), Hobbs (U.S. Pat. No. 1,778,496), Reeder Jr. (U.S. Pat. No. 2,679,696), Williams (U.S. Pat. No. 2,748,493), Appleton (U.S. Pat. No. 3,675,297), Stein (U.S. Pat. No. 5,167,073), and Stein et al. (U.S. Pat. No. 5,560,112). 
   Another prior art device is disclosed in Cloutier et al. (U.S. Pat. No. 6,237,233), which shows a doorframe adjustment apparatus that is horizontally collapsible. The Cloutier et al. device also suffers from some of the same disadvantages as does the Tuthill device. First, there are no clamping members to secure the frame to the device and preventing it from sliding relative to the edges of the device. As can be seen in FIG. 4 of Cloutier et al., members 2 and 3 may prevent movement of the frame in a first direction, toward the members, but nothing prevents the frame from sliding in a second direction away from the members 2 and 3. Secondly, the device does not provide a means for adjusting the height of the device, and therefore the frame, from the floor surface. Additionally, the Cloutier et al. device suffers from the disadvantage that it is not vertically collapsible and is therefore difficult to move, store, and remove from the door opening after the frame is secured. Finally, because the device is fixed in the vertical dimension, it cannot accommodate doors of varying size. This particular disadvantage is shared by the doorframe-hanging devices disclosed in Torstensen (U.S. Pat. No. 6,530,186) and McKay (U.S. Pat. No. 2,502,166). 
   Accordingly, a need exists for a construction tool for installing pre-hung doors that is adjustable in length and width to accommodate doors of varying dimensions and is capable of securely holding and properly aligning a doorframe during installation in a rough opening in a wall, while at the same time, allowing a worker to pass through the doorway opening. 
   SUMMARY OF THE INVENTION 
   Briefly, in accordance with the present invention, disclosed is a device for securely holding a pre-hung doorframe in a rough opening of a wall so that the frame can be properly secured to the wall in a straight and plumb alignment. The device includes four slidably adjustable elements arranged in a rectangular shape. Each element has a separation line near its center. A plate spans the separation line and has a groove along its length. Two bolts, one on either side of the separation line, extend in a direction toward the inner area of the rectangle and ride inside the groove in the plate when the elements are separated at the separation line. In this way, the rectangle can be increased or decreased in both width and length. Nuts on the ends of the bolts can be tightened to secure the elements in a particular position. 
   The device is placed inside a pre-hung doorframe and slidably adjusted to meet the inner dimensions of the frame. The device has pairs of clamps along its elements which are used to attach and secure the frame to the device so that the device and frame can be placed within a rough opening in a wall and the frame will retain the rectangular shape of the device without being able to distort. The clamps can be used to attach the device and frame to the edges of the rough opening of the wall to further facilitate alignment of the frame with the wall. Advantageously, the device is rectangularly shaped and is completely open within its center, allowing workers to pass unencumbered through the doorway when the device is in place. 
   The frame, still attached to the device, is then leveled within the rough opening. A pair of telescoping feet attached to the base of the device allow the frame to be spaced from the floor surface and tilted to ensure proper leveling within the rough opening. Once the frame is level, shims are placed at various locations between the outside surface of the frame and an inside surface of the rough opening in the wall to provide proper contact with the opening. The device is provided with pass-through holes so that a screw or nail can be inserted into the frame, the shims, and finally the inside surface of the rough opening in the wall, to secure the frame in its properly aligned location. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The accompanying figures, where like reference numerals refer to identical or functionally similar elements throughout the separate views and which together with the detailed description below are incorporated in and form part of the specification, serve to further illustrate various embodiments and to explain various principles and advantages, all in accordance with the present invention. 
       FIG. 1  is a diagram illustrating one embodiment of a doorframe-hanging device; 
       FIG. 2  is a diagram illustrating a width expansion feature of a doorframe-hanging device; 
       FIG. 3  is a diagram illustrating a length expansion feature of a doorframe-hanging device; 
       FIG. 4  is a diagram illustrating a doorframe-hanging device attached to a doorframe; 
       FIG. 5  is a diagram illustrating a rough opening in a wall; 
       FIG. 6  is a diagram illustrating a doorframe-hanging device attached to a doorframe and partially inserted into a rough opening in a wall; 
       FIG. 7  is a diagram illustrating a doorframe-hanging device attached to a doorframe and fully inserted into a rough opening in a wall; 
       FIG. 8  is a diagram illustrating a doorframe-hanging device removed from a doorframe and a rough opening in the wall; 
       FIG. 9  is a diagram illustrating an embodiment of a doorframe-hanging device attached to a doorframe including a door and inserted into a rough opening in a wall; 
       FIG. 10  is a diagram illustrating a single door and frame mounted in a rough opening in a wall; 
       FIG. 11  is a diagram illustrating double doors and a frame mounted in a rough opening in a wall; 
       FIG. 12  is a diagram illustrating a close-up view of a section of a doorframe-hanging device, including a clamping pair, doorframe, and adjustable foot; 
       FIG. 13  is a diagram illustrating a close-up view of a section of a doorframe-hanging device, including a clamping pair, a second clamping pair, doorframe, adjustable foot, and lever-arm assembly; 
       FIG. 14  is a diagram illustrating a close-up view of a section of a doorframe-hanging device, including a doorframe, adjustable foot, and a second embodiment of a clamping pair; 
       FIG. 15  is a diagram illustrating a close-up view of a section of a doorframe-hanging device, including a doorframe, adjustable feet, a lever-arm assembly, and a second embodiment of a first and second clamping pair; 
       FIG. 16  is a diagram illustrating one embodiment of a doorframe-hanging device; and 
       FIG. 17  is a diagram illustrating one embodiment of a doorframe-hanging device located inside a rough opening in a wall. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   While the specification concludes with claims defining the features of the invention that are regarded as novel, it is believed that the invention will be better understood from a consideration of the following description in conjunction with the drawing figures, in which like reference numerals are carried forward. 
   Described now is an exemplary door installation device according to an exemplary embodiment of the present invention. Referring to  FIG. 1 , a door installation device  100  is shown in a horizontal position. The door installation device  100  includes a first side element  102 , a second side element  104 , a top element  106 , and a bottom element  108 . The elements  102 ,  104 ,  106 , and  108  are attached to each other in a rectangular arrangement, where each element meets the other at a 90-degree angle. The elements  102 ,  104 ,  106 , and  108  each have inwardly disposed wall elements  110 ,  112 ,  114 ,  116 ,  118 ,  120 ,  122 , and  124 . The sets of inwardly disposed wall elements  110  &amp;  112 ;  114  &amp;  116 ;  118  &amp;  120  and  122  &amp;  124  form an inwardly facing U-shaped channel  126 . The direction “inwardly” refers to a direction towards central region  101  of the frame  100 . 
   Each element  102 ,  104 ,  106 , and  108  is provided with a plurality of cutouts  128 , which are of proper dimension to, as will be explained later, allow a standard size screw or nail to pass through the element. The bottom element  108  includes a pair of telescoping feet  130  for leveling the device  100 , which will also be explained in the proceeding paragraphs. The side elements  102  and  104  and the top element  106  are provided with laterally opposing clamping pairs  132  &amp;  134 ,  136  &amp;  138 ,  140  &amp;  142 ,  144  &amp;  146 ,  148  &amp;  150 , and  152  &amp;  154  attached to their inwardly disposed wall elements  118  &amp;  120 ,  110  &amp;  112 , and  114  &amp;  116 , respectively, and extending outwardly beyond the elements  102 ,  104 , and  106 . The direction “outwardly” refers to a direction away from central region  101  of the frame  100 . 
   Each element  102 ,  104 ,  106 , and  108  is formed of two slidably adjustable adjacent pieces  102   a ,  102   b ,  104   a ,  104   b ,  106   a ,  106   b , and  108   a ,  108   b , respectively. The adjacent pieces are connected by a plate  156 ,  158 , which can be seen in  FIG. 1 and 160 ,  162 , which cannot be seen in  FIG. 1 , but are functionally the same as  156  and  158 . Each plate is provided with a linear groove  164 , which contains a pair of inwardly extending members  166 , such as a screw or bolt, and at least one member is attached to each adjacent piece  102   a ,  102   b ,  104   a ,  104   b ,  106   a ,  106   b , and  108   a ,  108   b , as can be seen in  FIG. 1 . The plates  156 ,  158 ,  160 , and  162  are secured in a particular position by lockdown nuts  168 . 
   Referring now to  FIG. 2 , it can be seen how plates  158  and  160  allow the inwardly extending members  166  to slide with the groove  164  in plates  158  and  160  and allow the adjacent pieces  106   a ,  106   b , and  108   a ,  108   b  to separate and increase the overall width of the device  100 . Arrows  202  and  204  indicate the direction of movement. In a similar manner,  FIG. 3  shows how inwardly extending members  166  slide within groove  164  in plates  156  and  162  to allow adjacent pieces  102   a ,  102   b , and  104   a  and  104   b  to separate and increase the overall length of the device  100 . Arrows  302  and  304  indicate the direction of movement. In  FIGS. 2 and 3  is can be seen how the overall length and width of the device  100  can easily be increased or decrease to accommodate a variety of frame sizes and for easy removal from a door opening, which will be explained in detail in the proceeding paragraphs. The invention is not limited to use of a plate to adjust the length or width and many other methods of adjusting the length or width of the device  100  can be used to achieve the same results. 
   Referring now to  FIG. 4 , a doorframe  400  having a top  402 , a first side  404 , and a second side  406  is placed around the device  100  and secured to the device  100 . As explained in the previous paragraph, the dimensions of device  100  can be adjusted to fit within a variety of frame sizes, both standard and custom, for single or double doors. Once the device  100  is properly sized to fit within and against the frame  400 , clamping pairs  140  &amp;  142 , and  144  &amp;  146  located on the first element  102 , clamping pairs  132  &amp;  134 , and  136  &amp;  138  on the second element  104 , and clamping pairs  148  &amp;  150 , and  152  &amp;  154  on the top element  106  are utilized to secure the frame tightly and securely against the device  100 . A close-up view of a clamp  134  securing a portion  406  of frame  400  to element  104  is shown in  FIG. 12 . The clamp  134  has an L-shaped leg at one end and, used in conjunction with the device  100 , constrains the frame from moving. An opposing clamp  132  on the opposite side of element  104  additionally prevents the frame from moving away from element  104 . 
     FIG. 5  shows a rough opening  502  in a wall  504  of a building, which includes vertical studs  506  and  508  and a header  510 . It is within the rough opening  502  that a pre-hung door is to be installed. However, to allow for material and workmanship tolerances, the studs  506  and  508  and header  510  are fixed so as to create an opening that is larger than the expected maximum dimensions of the doorframe  400 . Additionally, due to defects in material, such as warping or twisting, or workmanship defects, the studs  506  and  508  may not be plum and the floor  512  and/or header  510  may not be completely level. If these defects are not compensated for, the door will not close properly. Therefore, the frame must be attached in and to the rough opening  502  so that the frame is secure, not distorted from its rectangular alignment, and within a single plane. 
   Referring now to  FIG. 6 , the device  100  can be seen expanded to fit snuggly against an inner surfaces of a frame  400 . The device is in the horizontal position shown in  FIG. 1 , with the exception of being rotated 180 degrees, so that the telescoping feet  170  cannot be seen in  FIG. 6 . The device  100  is securely attached to the frame  400  via clamp sets  132  &amp;  134 ,  136  &amp;  138 ,  140  &amp;  142 ,  144  &amp;  146 ,  148  &amp;  150 , and  152  &amp;  154 . The device  100  is preferably constructed of a rigid material, such as metal, plastic, composite, or other similar materials, so that the frame  400  and device  100  can be moved and positioned without distorting frame  400  from its rectangular configuration (90-degree angled corners) within a single plane with straight edges  402 ,  404 , and  406 . Arrow  602  illustrates the movement of the device  100  and frame  400  to fit within the opening  502 . 
     FIG. 7  shows the device  100  and frame  400  positioned within the rough opening  502 . Once in position, a level (not shown) can be placed inside the U-shaped channel  126  of the bottom element  108 . The adjustable members  130  (not shown) can be telescoped in and out to level the device  100  and frame  400 . The members  130  can also be utilized to space the frame  400  off of the floor surface a proper distance. Additionally, a level (not shown) can be used along the first element  102  or second element  104  to ensure that the frame  400  is plumb, or vertical, before attaching the frame  400  to the rough opening  502 . As previously mentioned, the rough opening  502 , formed by studs  506  and  508 , header  510  and floor  512 , is slightly larger than the outer dimension of the frame  400 . 
   As is also shown in  FIG. 7 , the clamping pairs  140  &amp;  142 , and  144  &amp;  146  located on the first element  102  and the clamping pairs  132  &amp;  134 , and  136  &amp;  138  on the second element  104  can be extended to clamp onto the studs  506  and  508  to secure the device in the plane of the opening  502  in the wall  504 . It is noted that this method cannot be used if the walls are finished, meaning the studs are covered with drywall material. A second method, described later, may be employed in this situation. 
     FIG. 7  diagrammatically illustrates via arrows  702 ,  704 ,  706 , and  708  where shims  710 ,  712 ,  714 , and  716  may be placed in order to plum and level doorframe  400  in the rough opening  502 . Once the shims  710 ,  712 ,  714 , and  716  are in the proper location, nails or screws can be driven via cutouts  128  (not shown) through the frame  400 , through the shims  710 ,  712 ,  714 , and  716 , and into the studs  506  and  508  to secure the frame  400  within the opening  502 . Also shown in  FIG. 7  are two hinges  718  and  720 , which are attached to the frame section  406 . For the method of installing the doorframe, so far described and shown in the drawings, the pre-hung door (not shown) has been separated from the frame  400  by removing a pin (not shown) from the hinges  718  and  720 . Once the frame is in place, as will be described below, the door can easily be reattached to the hinges  718  and  720 . If a set of double doors is to be installed in the doorway  502 , a second set of hinges can simply be provided on the opposite side  406  of the doorframe  400 . 
   Referring now to  FIG. 8 , after the frame  400  is properly and permanently secured to the opening  502 , the device  100  can then be removed. The removal of the device  100  begins with the clamping pairs  132 ,  134 ,  136 ,  138 ,  140 ,  142 ,  144 ,  146 ,  148 ,  150 ,  152 , and  154  being released from the edges  402 ,  404 ,  406  of the frame  400  and/or the studs  506  and  508 . Once the device  100  is no longer attached to the frame  400  via the clamping pairs  132 ,  134 ,  136 ,  138 ,  140 ,  142 ,  144 ,  146 ,  148 ,  150 ,  152 , and  154 , the locking nuts  168  are loosened so the extending members  166  can slide toward one another within the groove  164  in the plates  156 ,  158 ,  160 ,  162 . This allows the device  100  to shrink in size and easily slide out of the opening in the doorway  502 , as is shown in  FIG. 8 . 
   A level doorframe  400  is now installed in a rough opening  502  of a building. A door, or doors, can now be attached to hinges  718  and  720  attached to the frame  400 , and the door(s) will swing true and properly close within the frame. 
   As described above, pre-hung doors come from the factory as a door mounted to an assembled doorframe  400 . In the methods described above, the doorframe  400  is mounted by removing the door from the frame  400  during installation and then reattaching the door once the frame  400  is mounted. However, a timesavings can be realized if the frame can be installed without having to remove the door. To mount the frame  400 , the door must be in an open position during the installation, which adds a large weight to one side of the frame. One difficulty realized in the prior art is that the weight of the door causes the frame to tilt in the direction of the open door. This problem is overcome by the embodiment shown in  FIG. 9 . 
   In  FIG. 9 , a pair of foldable lever arms  902  and  904  are shown attached to the bottom element  108  of device  100 . Each of the foldable lever arms  902  and  904  is provided with a telescoping foot  906  at an end furthest away from the device  100 . The foldable lever arms  902  and  904  and the feet  906  are provided to assist in leveling the frame  400  with a wall  504  in a rough opening  502  in a building and counteract the weight of the door  914  attached to the frame  400  by hinges  718  and  720 . For proper installation and for the door to function properly once installed, the upper  908  and lower  910  portions of the frame  400  must be in the same plane as the wall  504 . By adjusting the telescoping feet  906 , the upper portion of the device  100  and frame  400  is adjusted, as shown by direction arrow  912 , to be plumb, and/or in a shared plane with the wall  504 . 
   A closer view of a telescoping member  130  and a clamping pair  134  and  132  can be seen in  FIG. 12 . A close-up view of a foldable lever arm  904 , telescoping members  130  and  906 , and clamping pair  132  and  134  are diagrammatically shown in  FIG. 13 . An additional clamping pair  1302  and  1304  is also shown in  FIG. 13 . The additional clamping pair  1302  and  1304  can be used to increase support of the frame  400 , or can be used, as shown in  FIG. 7 , to attach the device  100  to the studs  506  and  508 , or as will be described in the proceeding paragraph to attach to the wall  504 . 
     FIG. 10  shows a complete installation of a single door  914  in wall  504 . If properly aligned, the door  914  will have an even spacing between the wall  504  and both sides and the top of the door  914 . Additionally, the door  504  can be opened without the door  914  scraping the floor  512 . 
     FIG. 11  shows a double set of doors  1102  and  1104 . It is even more important that the doorframe  400  be accurately aligned when installing double doors. Not only is it important, as in a single door, that the doors have an even spacing between the sides and top of the door and the wall  504 , but also the doors  1102  and  1104  must match up properly with each other. Any skew in the frame  400  will cause the space  1106  between the doors  1102  and  1104  to be non-uniform. 
   An additional function of the clamping pairs can be seen in  FIG. 12 . In  FIG. 12 , a gap  1202  is shown between stud  506  and frame section  406 . The clamping pair  132  and  134  can be extended beyond the frame section  406  to take up the gap  1202  and physically contact the stud  506 . In this manner, the clamping pair  132  and  143  works to secure the device  100  and frame  400  within the opening  502  until the frame  400  can be permanently secured with nails or screws. 
   An alternative use of clamping pairs  132 ,  134 ,  136 ,  138 ,  140 ,  142 ,  144 ,  146 ,  148 ,  150 ,  152 , and  154  is shown in  FIGS. 14 and 15 , where a finished wall  504  is shown. A finished wall is any wall with a framework of studs covered with a material such as sheet rock, plywood, wallboard, or other similar materials to provide a relatively smooth surface and hide the studs. In  FIGS. 14 and 15 , clamp  134  is turned over so that an L-shaped portion  1402  of clamp  134  faces away from the wall  504 . As can be seen in the drawing, clamp  134  extends beyond frame section  406  and contacts the wall  504 . When used in this manner, the clamps ensure that the device  100 , and therefore the frame  400  share the same plane as the wall  504 . 
     FIG. 15  shows an embodiment of the present device  100  with the lever arm  904  and an additional clamp  1302  turned in the reverse direction, as described in the preceding paragraph. The additional clamp  1302  provides added stability and additional contact surface area for the wall  504 . 
   One alternative embodiment of the present invention is shown in  FIG. 16 . The door installation device  1600  includes two upper corner brackets  1602  and  1604 , each having an L-shaped outer section  1602   a ,  1604   a  and an L-shaped inner section  1602   b ,  1604   b . The L-shaped outer  1602   a ,  1604   a  and inner  1602   b ,  1604   b  sections are used to sandwich two portions ( 406  and  402  in bracket  1602  and  404  and  402  in bracket  1604 ) of the doorframe  400  sections and hold them at an approximately 90-degree angle. A bar  1606  passes through outer  1602   a ,  1604   a  and inner  1602   b ,  1604   b  sections of the brackets  1602  and  1604 . The bar  1606  further includes two devices  1608  and  1610  disposed on opposing sides of the bar  1606 , which function as positioners and tensioners for the inner sections  1602   b  and  1604   b . The tensioners are slidably, releasably affixed to bar  1606  and permanently affixed to the inner sections  1602   b  and  1604   b . In this manner, the upper corner brackets  1602  and  1604  can accommodate frames of varying sizes. 
   The embodiment shown in  FIG. 16  further includes two lower corner brackets  1612  and  1614 . Each lower corner bracket  1612  and  1614  includes an outer section  1612   a  and  1614   a  and an L-shaped inner section  1612   b  and  1612   b . The outer  1612   a ,  1614   a  and inner  1612   b ,  1614   b  sections are used to sandwich a side  406  and  404 , respectively, of the doorframe  400  and hold them at an approximately 90-degree angle to the floor surface  512 . A second bar  1616  passes through outer  1612   a ,  1614   a  and inner  1612   b ,  1614   b  sections of the brackets  1612  and  1614 . The second bar  1616 , like the first bar  1606 , further includes two devices  1618  and  1620  disposed on opposing sides of the bar  1616 , which function as positioners and tensioners for the inner sections  1612   b  and  1614   b . The tensioners are slidably, releasably affixed to bar  1616  and permanently affixed to the inner sections  1612   b  and  1614   b . In this manner, the lower corner brackets  1612  and  1614  can accommodate frame sections of varying dimensions. 
   In one embodiment, the outer sections  1602   a ,  1604   a ,  1612   a , and  1614   a  are permanently fixed to the bars  1606  and  1616 . The inner sections  1602   b ,  1604   b ,  1612   b , and  1614   b  are not fixed on the bars  1606  and  1616 . Each of the four tensioning devices  1608 ,  1610 ,  1618 , and  1620  is connected at one side to each of the inner sections  1602   b ,  1604   b ,  1612   b , and  1614   b  and has a sliding collar  1622  containing the bar  1606  or  1616  at the opposite side. Each collar  1622  has a tightening screw  1624  that passes through the collar  1622  and contacts the bar  1606  or  1616 . The collar  1622  is provided with threads so that when tightening screw  1624  is turned, pressure is placed on the bar  1606  and  1616  to secure the collar  1622 , and in turn, the entire tensioning device  1608 ,  1610 ,  1618 , and  1620  in its position. 
   Additionally, the portions of bars  1606  and  1616  that extend beyond the outer sections  1602   a ,  1604   a ,  1612   a , and  1614   a  butt up against the wall  504  when the device  1600  is fully inserted into a rough opening in a wall. The bars  1606  and  1616 , therefore, serve at least three functions: 1) to align the corner brackets; 2) to provide tensioning support for the inner portions  602   b ,  1604   b ,  1612   b , and  1614   b ; and 3) to align the frame with the plane of the wall  504 . 
   As with the installation methods so far described, the rough opening  502 , formed by studs  506  and  508 , header  510  and floor  512 , is slightly larger than the outer dimension of the frame  400 . Shim material  712  and  714  is placed between the frame  400  and vertical studs  506  and  508  defining the rough opening  502 . As can be seen in  FIG. 17 , the outer sections  1602   a ,  1604   a ,  1612   a , and  1614   a  of the corner brackets  1602 ,  1604 ,  1612 , and  1614  are located between the vertical studs  506  and  508  and header  510 . The shims  714  and  712  allow the frame to be installed while gap  1702  and  1704  remains between the sides of the frame  400  and the studs  506  and  508 . This gap  1702  and  1704  allows the outer sections  1602   a ,  1604   a ,  1612   a , and  1614   a  of the corner brackets  1602 ,  1604 ,  1612 , and  1614  to be removed once the frame  400  is securely attached to the opening  502  in the wall  504  and the tensioners  1608 ,  1610 ,  1618  and  1620  are released. 
   The embodiment just described and shown in  FIGS. 16 and 17  provides the advantage of having less material and therefore, a low total weight and ease of storage when not in use, while also being able to maintain the doorframe in its proper orientation and alignment during installation in a rough opening in a wall. 
   In each of the embodiments shown and described, the shims  710 ,  712 ,  714 ,  716  and any gaps between the frame  400  and the rough opening in the wall  502  can be concealed by placing a cosmetic cover, commonly referred to as a “case molding,” around the edges of the doorframe. The final step of installing the case molding gives the perfectly aligned doors a clean, professional appearance. 
   While the preferred embodiments of the invention have been illustrated and described, it will be clear that the invention is not so limited. Numerous modifications, changes, variations, substitutions and equivalents will occur to those skilled in the art without departing from the spirit and scope of the present invention as defined by the appended claims.