You are an expert at summarizing long articles. Proceed to summarize the following text:

You are an expert at summarizing long articles. Proceed to summarize the following text: 
This invention relates to a removable window safety barrier. In preferred embodiments, this barrier includes two vertical frame members, one at a first end of the barrier, and one at a second end, joined together by two horizontal frame members at third and fourth ends. Each of the vertical frame members comprises a flat metal plate having a flange or a protrusion at each end of the vertical member. Each of these protrusions includes a hole of suitable size and shape to engage, and be supported by, a lag bolt, preferably an L-shaped lag bolt. The vertical members, in preferred embodiments, have a length in the range of about 2 to about 2.5 feet. The two horizontal frame members are metal bars made of four-sided, hollow, metal stock, preferably square metal stock. More preferably, the metal stock is half-inch square steel bars that are about 2.5 to about 3.0 feet in length. 
     In the preferred embodiment, the barrier also includes two, three or more additional horizontal members, with each horizontal member preferably made of the same metal stock as the two horizontal frame members. Preferably, the horizontal members are spaced nearly equal distances from one another. 
     The barrier may also include one or more additional vertical support members, each preferably attached to each of the horizontal members, by welding or otherwise. The horizontal members are joined to the vertical end members by welding, brazing, by hardware such as nuts and bolts, or otherwise. 
     The barrier is preferably installed in a window frame just above the window sill, and is positioned to prevent a small child from going through the window. The preferred embodiment is positioned in a window frame just above the sill on four lag bolts, two positioned near the bottom of the frame above the sill, and two near the top of the frame. These lag bolts preferably screw into, or otherwise penetrate securely into the window frame leaving, near the sill, two pins pointing upwardly from the plane of the window sill, one from each side of the frame. Near the top of the frame are two additional pins pointing downwardly toward the window sill, one from each side of the frame. 
     The barrier is removably mounted on the lag bolts by placing the holes of the barrier onto the downwardly-pointing pins, and moving the barrier upward until the holes at the bottom of the vertical members of the barrier are positioned over the upwardly-pointing pins. The holes at the bottom of each vertical member of the barrier are then seated on the upwardly-pointing pins, and the barrier is lowered to rest upon the two upwardly-pointing lag bolts. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention can better be understood by reference to the drawings in which: 
     FIG. 1 shows an elevation view of a first embodiment of the barrier, removably seated in a window; and 
     FIG. 2 shows an elevation view of a second embodiment of the barrier, removably seated in a window. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1 shows window  10  with raised sash  11  having opening  12  above sill  13 . Screwed into sides  14  and  15  of window  10  are L-shaped lag bolts  16  and  17 . Each of lag bolts  16  and  17  includes a threaded shank  18  and integrally formed pin  19 . Lag bolts  16  and  17  are screwed into side members  14  and  15  of window  10 , such that pins  19  point upwardly from the plane of sill  13 . Each of lag bolts  20  and  21  is screwed into window sides  14  and  15  with pins  19  pointing downwardly toward the plane of sill  13 . 
     Inserted into opening  12  is barrier  25 . Barrier  25  includes vertical frame members  26  and  27  made of flat metal stock. Vertical frame member  26  has, at its upper end, outwardly extending flange  28 , and at its lower end, outwardly extending flange  29 . Vertical frame member  27  has, at its upper end, outwardly extending flange  30 , and at its lower end, outwardly extending flange  31 . Each of flanges  28 ,  29 ,  30  and  31  has a round hole of a size and shape suitable to fit onto pins  19 . 
     Barrier  25  also includes horizontal frame members  35  and  36 , each welded to the inner surface of vertical frame member  27  at one end, and to the inner surface of vertical frame member  26  at the other end. Horizontal members  35  and  36  are made of square, hollow, steel bars. Also welded between the inner surface of vertical members  27  and  27  are horizontal members  37 ,  38  and  39 . Horizontal members  36  and  29  are spaced apart about the same distance as horizontal members  38  and  39 . Horizontal members  38  and  37  are spaced apart about the same distance as are members  37  and  35 . 
     Frame  25  also includes an additional vertical member  40  made of the same square metal bar stock as frame numbers  35  and  36 , welded midway between vertical frame members  27  and  26  to each of horizontal members  35 ,  37 ,  38 ,  39  and  36 . 
     To remove barrier  25  from its position shown in FIG. 1, a user lifts barrier  25  upwardly until the holes in flanges  29  and  31  disengage from pins  19  on lag bolts  16  and  17 . Barrier  25  is then moved toward, or away from, the plane of lag bolts  16  and  17 , and is lowered until flanges  30  and  28  disengage from pins  19  on lag bolts  20  and  21 . 
     Barrier  25  can be reinstalled by inserting the holes on flanges  30  and  28  onto pins  19  of lag bolts  20  and  21 , and moving barrier  25  upwardly until the holes in flanges  29  and  31  are over the pins  19  on lag bolts  16  and  17 . Barrier  25  is then lowered onto lag bolts  16  and  17 , with pins  19  penetrating through the holes in flanges  31  and  29 . In this way, barrier  25  can be positioned in window  10  to prevent small children from passing through window  10 , but can easily be removed from inside or outside window  10  in case of fire or other emergency. 
     FIG. 2 shows window  110  with raised sash  111  having opening  112  above sill  113 . Screwed into sides  114  and  115  of window  110  are L-shaped lag bolts  116  and  117 . Each of lag bolts  116  and  117  includes a threaded shank  118  and integrally formed pin  119 . Lag bolts  116  and  117  are screwed into side members  114  and  115  of window  110 , such that pins  119  point upwardly from the plane of sill  113 . Each of lag bolts  120  and  121  is screwed into window sides  114  and  115  with pins  119  pointing downwardly toward the plane of sill  113 . 
     Inserted into opening  112  is barrier  125 . Barrier  125  includes vertical frame members  126  and  127  made of flat metal stock. Vertical frame member  126  has, at its upper end, outwardly extending flange  128 , and at its lower end, outwardly extending flange  129 . Vertical frame member  127  has, at its upper end, outwardly extending flange  130 , and at its lower end, outwardly extending flange  131 . Each of flanges  128 ,  129 ,  130  and  131  has a round hole of a size and shape suitable to fit onto pins  119 . 
     Barrier  125  also includes horizontal frame members  135  and  136 , each welded to the inner surface of vertical frame member  127  at one end, and to the inner surface of vertical frame member  126  at the other end. Horizontal members  135  and  136  are made of square, hollow, steel bars. Also welded between the inner surface of vertical members  127  and  127  are horizontal members  137 ,  138  and  139 . Horizontal members  136  and  129  are spaced apart about the same distance as horizontal members  138  and  139 . Horizontal members  138  and  137  are spaced apart about the same distance as are members  137  and  135 . 
     Frame  125  also includes two additional vertical members  140  made of the same square metal bar stock as frame numbers  135  and  136 , welded between vertical frame members  127  and  126  to each of horizontal members  135 ,  137 ,  138 ,  139  and  136 . 
     To remove barrier  125  from its position shown in FIG. 1, a user lifts barrier  125  upwardly until the holes in flanges  129  and  131  disengage from pins  119  on lag bolts  116  and  117 . Barrier  125  is then moved toward, or away from, the plane of lag bolts  116  and  117 , and is lowered until flanges  130  and  128  disengage from pins  119  on lag bolts  120  and  121 . 
     Barrier  125  can be reinstalled by inserting the holes on flanges  130  and  128  onto pins  119  of lag bolts  120  and  121 , and moving barrier  125  upwardly until the holes in flanges  129  and  131  are over the pins  119  on lag bolts  116  and  117 . Barrier  125  is then lowered onto lag bolts  116  and  117 , with pins  119  penetrating through the holes in flanges  131  and  129 . In this way, barrier  125  can be positioned in window  110  to prevent small children from passing through window  110 , but can easily be removed from inside or outside window  110  in case of fire or other emergency.

Summary:
A removable window safety barrier includes two vertical frame members, two horizontal frame members, and additional horizontal and vertical members attached to the horizontal and vertical frame members. The barrier includes at each end of the vertical frame members flanges having holes of suitable size and shape to engage and be supported by pins affixed to the sides of a window with two such pins pointing upwardly from the bottom of the window, and two such pins facing downwardly from the top of the window.