Abstract:
A metal frame and glass panel structure has a metal shoe having a receiving channel, the receiving channel having at least one smooth side surface and an opposite side surface spaced apart from the smooth side surface; a glass panel positioned within the channel against the smooth side surface and spaced apart from the opposite side surface; at least two independent expandable pressure units positioned within the channel between the glass panel and the opposite side surface of the channel; and means within the pressure units for generating a pressure against the opposite side surface of the channel whereby the pressure units are forced against the glass panel to secure the glass panel within the channel. A pair of adjustment screws is provided in the channel, upwardly extending from the bottom thereof, for squaring the glass panel with the shoe. A strip of double-face tape is provided on the one side surface of the channel to prevent the glass panel from slipping relative to the shoe.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional of U.S. Patent Application Ser. No. 862,994, filed May 14, 1986, now U.S. Pat. No. 4,680,903 entitled DOOR SHOE ASSEMBLY. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention relates generally to metal frame and glass structures and more particularly to a new glazing system for such structures. 
     Tempered glass door and sidelight structures have recently enjoyed an increase in popularity and use, particularly in office and other commercial buildings. The popularity of such structures is primarily due to the enhanced aesthetic effect they offer over the more traditional, non-transparent door and sidelight structures. 
     Typically, glass door and sidelights are installed in a metal frame and held therein by any one of a variety of adhesives or fixatives. These assemblies, however, require costly set-up and fixtures and require considerable skill to properly set and bond the tempered glass panel in place. Furthermore, these assemblies are particularly disadvantageous when the glass panel and metal frame is to be assembled on-site. 
     Mechanical-type glazing systems are also known, such as for example, U.S. Pat. No. 4,423,582 to Yates. These mechanical glazing systems typically teach the use of a continuous structure, such as for example a wedge, to apply pressure to the glass panel. The use of a continuous structure, however, presents several disadvantages. For example, a continuous structure attempts to straighten out the natural warp, bow or kink of the glass panel by spanning from high point to high point and trying to level the valley therebetween. As such, the glass panel is subjected to increased stress, thus making the glass panel more susceptible to breakage. Another disadvantage in using a continuous structure is that they tend to concentrate the load on the lower edge of the glass panel due to the distortion of the metal frame when the pressure is applied. This concentration of load, in turn, makes the glass panel more susceptible to breakage. 
     Still another disadvantage of the known mechanical glazing systems arises when the use of thick glass panels is desired. As the thickness of the glass panel increases, the side walls of the door shoe defining the channel become thinner in order to accomodate the thicker glass. The reduced thickness of the side walls makes the walls more susceptible to bending and breaking. When a 3/4 inch glass panel is used, the side walls of the shoe have become so thin that they will no longer withstand the pressure generated against them by the glazing structure. As such, when thick glass panels are desired, a larger door shoe must be provided, which reduces the overall utility of the system. 
     I have invented a mechanical glazing system which overcomes the above-mentioned disadvantages of the known glazing systems by providing a plurality of independent expandable pressure units to secure the glass panel within the metal frame whereby an even pressure is exerted on the glass panel to reduce the stress on the glass. The use of independent pressure units is particularly advantageous when thick glass panels are desired, in which case a localized recess can be made in the side wall of the channel to accomodate the panel and the pressure units without the concomitant structural impairment of the door shoe observed in the prior art systems. The present invention is also easier and cheaper to manufacture and assemble than existing glazing systems. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is an object of the invention to provide a novel glazing system for use in metal frame and glass panel structures which eliminates the disadvantages of present mechanical glazing systems. 
     It is another object of the invention to provide a glazing system which uses a plurality of independent expandable pressure units to hold the glass panel securely to the metal frame. 
     It is another object of the invention to provide a metal frame and glass panel structure which uses a least two independent expandable pressure units placed within a channel in the metal frame whereupon actuation of the units creates an even pressure on the glass panel. 
     It is another object of the invention to accomplish the above objects by providing a plurality of pressure units comprising pressure blocks disposed in the channel between one side thereof and the glass panel wherein said pressure blocks include adjustable pressure generating means for generating a pressure on said frame whereby said pressure blocks exert an even pressure on said glass panel. 
     It is a further object of the invention to provide means for preventing said glass panel from slipping on said frame. 
     It is a further object of the invention to provide means for facilitating the proper alignment of the glass panel within the frame. 
     These and other objects of the invention will become apparent upon a reading of the following detailed description of the invention with reference to the drawing figures and the appended claims. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a front elevational view of a metal frame and glass panel structure, in this case a door, in accordance with the invention showing the position of the independent expandable pressure units illustrated in phantom in the bottom shoe of the door. 
     FIG. 2 is an enlarged sectional view of the invention taken along line 2--2 of FIG. 1. 
     FIG. 3 is an enlarged sectional view of the invention as in FIG. 2, showing the frame and glass panel in the assembled condition with the pressure units shown in expanded condition and the distortion of shoe being exaggerated for purposes of illustration. 
     FIG. 4 is a perspective view of the independent expandable pressure unit of the invention showing the ball and screw arrangement therein. 
     FIG. 5 is a perspective view of another embodiment of the independent expandable pressure unit of the invention as seen from the opposite side of the unit from that in FIG. 4 and showing the cylinder and screw arrangements. 
     FIG. 6 is a sectional view of the embodiment of the pressure unit of FIG. 5 taken along line 6--6 of FIG. 5. 
     FIG. 7 is a sectional view of still another embodiment of the pressure unit of the invention wherein the transverse bore is perpendicular to the tapped bore and the screw is cone-pointed. 
     FIG. 8 is an exploded perspective view of a preferred embodiment of the invention shown partially broken away to illustrate placement of the pressure unit in the channel. 
     FIG. 9 is a sectional view of the preferred embodiment of the invention in assembled form. 
     FIG. 10 is a sectional view of the preferred embodiment and taken along line 10--10 of FIG. 9. 
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Referring first to FIG. 1, a metal frame and glass panel structure in accordance with the invention is shown. In the embodiment shown, the metal frame and glass panel structure is a door 10 which comprises a glass panel 11 and top and bottom metal shoes 12 and 13, respectively. As seen in FIG. 1, metal shoes 12,13 are elongate rigid structures extending the entire width of the glass panel 11. Metal shoes 12,13 are preferably made of aluminum or brass for aesthetic purposes, although it is to be understood that other metals are also suitable. Furthermore, it is to be understood that shoes 12,13, although preferably constructed as a continuous metal extrusion, may be made of smaller metal extrusions fitted together so as to form a substantially continuous piece. Also shown in FIG. 1, illustrated in phantom in bottom shoe 13, are a plurality of independent expandable pressure units 14 which are more fully described below. 
     With reference to FIGS. 2, and 3, the cooperation of the various elements comprising the invention is clearly illustrated therein, particular reference being made to bottom shoe 13 although it is to be understood that the following applies equally to top shoe 12 of structure 10. As seen in FIG. 2, bottom shoe 13 is provided with an open channel 15 which extends longitudinally through shoe 13. In the embodiment shown in Figs. 2 and 3, channel 15 is provided with substantially parallel, spaced apart side surfaces 16,17 which are substantially parallel to the faces 18,19 of shoe 13. Bottom wall 20 of channel 15 separates the channel from web opening 21 of shoe 13. 
     Although the embodiment illustrated in FIGS. 2 and 3 is shown as having a substantially H-shaped metal shoe, it is to be understood that other suitable shapes are also possible. Furthermore, it is to be understood that side surfaces 16,17 need not be parallel to one another and side surface 16 need only be smooth and disposed substantially parallel to the plane of the glass panel. 
     Glass panel 11 is positioned within channel 15 against one side surface thereof, such as side surface 16, and spaced apart from the other side surface 17. A strip of adhesive, such as double-faced tape 22 may be provided, if desired, along the side surface 16 adjacent to the glass panel 11 to prevent any slip between the glass panel 11 and the shoe 13. 
     The adhesive material also provides a compressible cushion against the glass panel which will follow the natural bow, warp or kink of the glass panel when the glass panel is forced against the side surface 16, as described below, and thus reduces the stress on the glass panel. 
     It may also be desirable to adjust the vertical position of glass panel 11 relative to shoe 13, such as for example when it is desired to square the glass panel with the shoe. To this end, adjustment screws 23 (only one being shown) are provided in the channel 15. The adjustment screws 23, which are preferably plastic, are disposed within tapped bores 24 in bottom wall 20 and extend upwardly into channel 15. The adjustment screws 23 are positioned so as to be underneath and in contact with glass panel 11 in channel 15. It is preferable to position adjustment screws 23 near the longitudinal ends of channel 15 so that upon proper adjustment of the screws, glass panel 11 may be adjusted vertically relative to bottom wall 20 of channel 15 to square the glass panel 11 properly with shoe 13. 
     Positioned within channel 15 between the glass panel 11 and the other side surface 17 of the channel are at least two pressure units 14 in spaced apart relation to one another (see FIG. 1). Pressure units 14, as more fully described hereinafter, form independent expandable pressure units for retaining the glass panel 11 within the channel 15 of door shoe 13. The number of pressure units used in a particular structure is a function of the width of the glass panel and shoe, it being understood that at least two pressure units are required for the proper functioning of the invention. The pressure units are preferably spaced 4 to 6 inches apart on center. 
     FIGS. 8-10 illustrate a preferred embodiment of the invention with various other embodiments of the pressure units 14 being illustrated in FIGS. 2-7. With reference first being made to the embodiment of FIG. 4, pressure unit 14 comprises a pressure block 25 which is illustrated as being of generally flattened cubicial shape, it being understood that other shapes are also suitable, such as that shown in FIGS. 8-10. Pressure block 25 is provided with a vertically extending tapped bore 26 and a transverse bore 27 which intersects with tapped bore 26. Disposed within transverse bore 27 for sliding movement therein is ball 28 which is sized so as to be closely received within transverse bore 27. An adjustment screw 29 is disposed within tapped bore 26 and is sized so as to contact ball 28 in transverse bore 27 and move ball 28 within the transverse bore when screw 29 is advanced within tapped bore 26. As seen in Figs. 2-4, transverse bore 27 is preferably angled upwardly towards side surface 17 of channel 15 when pressure unit 14 is disposed within the channel. 
     With reference to FIGS. 5 and 6, another embodiment of the pressure unit 14 is illustrated and comprises a pressure block 525 having a vertical tapped bore 526 and a transverse concave recess 527 of substantially U-shape configuration. A cylindrical member 528 is slidably disposed within transverse recess 527 and is of such diameter that cylinder 528 is closely received within the transverse recess. An adjustment screw 529 is disposed within the tapped bore 526 which, when advanced within the tapped bore, will push cylinder 528 outwardly from transverse recess 527. 
     With reference to FIG. 7, still another embodiment of the pressure unit 14 is illustrated as comprising a pressure block 725 having a vertical tapped bore 726 and a transverse bore 727 which intersects tapped bore 726. A ball 728 is slidably disposed in and closely received by transverse bore 727. An adjustment screw 729 is disposed within tapped bore 726 which will push ball 728 outwardly from transverse bore 727 when advanced within tapped bore 726. In the particular embodiment illustrated in FIG. 7, transverse bore 727 is perpendicular to tapped bore 726 and adjustment screw 729 is a cone-pointed screw. 
     As seen from the Figures, the element disposed within the transverse opening, whether it be a ball or a cylinder, is of substantially circular cross-sectional shape which is required to provide a pivotal contact with side surface 17 of channel 15 and the walls of the transverse opening in the pressure block 25 which, in turn, assures an even pressure contact between pressure block 25 and glass panel 11. The modifications illustrated for the configuration of the transverse opening and the adjustment screw are then dependent upon the type of element to be used to provide the pivotal contact. 
     With particular reference again to FIGS. 2-4, pressure units 14 are positioned within channel 15 in the space between glass panel 11 and side surface 17. Adjustment screw 29 projects into an oversized aperture 30 in bottom wall 20. The aperture 30 is oversized to facilitate the positioning of pressure unit 14 in channel 15 and to facilitate the adjustment of screw 29 when the pressure units are in position. Pressure block 25 is preferably provided with an upwardly projecting flange 31 which extends substantially across the top surface of pressure block 25. Flange 31 cooperates with an inwardly and then downwardly projecting cover lip 32 of side surface 17 of channel 15 to help retain the pressure blocks 14 in position during assembly. As seen in the figures, cover lip 32 is preferably formed continuous with shoe 13 for aesthetic purposes. 
     The assembly of the invention will now be described with reference to the embodiments illustrated in FIGS. 2-7. First, the strip of double-faced tape 22 is applied to side surface 16 of channel 15 leaving the protective cover on the side of the tape that is to be adhered to the glass panel 11. Pressure units 14 including pressure blocks 15, ball 28 and screw 29 are then positioned within channel 15 with the ball 28 being substantially disposed within transverse bore 27 as seen in FIG. 2. Ball 28 may temporarily be held in place by a drop of silicone sealant (not shown), if desired. Pressure units 14 are loosely held in place by screw 29 in oversized hole 30 and by the flange 31 and cover lip 32 configuration mentioned above. Glass panel 11 is then positioned within channel 15 and is squared with shoes 12 and 13 by adjusting screws 23. Glass panel 11 is then removed from the channel, and the protective cover of the double-faced tape strip 22 is removed. Glass panel 11 is again placed within channel 15 and screw 29 is advanced within tapped bore 26. The advancement of screw 29 causes ball 28 to slide within transverse bore 27 upwardly and outwardly towards side surface 17 to expand pressure unit 14, thereby forcing pressure block 25 against glass panel 11 which in turn is forced against tape 22 and side surface 16 whereby glass panel 11 is secured within channel 15. 
     As seen in FIG. 3, the localized pressure created by the advancement of ball 28 against side surface 17 will cause side surface 17 to distort outwardly, the degree of distortion being a function of the yield characteristics of the metal used for the shoe. Despite the distortion in side surface 17, the pressure transmitted by pressure block 25 to glass panel 11 will always be evenly distributed on glass panel 11 due to the pivoting connections between ball 28, side surface 17, and pressure block 25 along transverse bore 27. Thus, a localized pressure is created on side surface 17 by ball 28 and this localized pressure is transmitted to a force on the glass panel which is evenly distributed along the surface of contact between the pressure block 25 and the glass panel 11. 
     As can be seen in FIGS. 2 and 3, the advancement of ball 28 towards side surface 17 in effect expands the dimensions of pressure block 25 in the lateral directions. It is also evident from the Figures that pressure blocks 25 remain stationary in the vertical directions and substantially stationary in the lateral directions when the ball 28 is advanced in transverse bore 27. 
     With reference to FIGS. 8-10, the preferred embodiment of the invention comprises a door shoe 300 having a channel 301 therein, with the channel 301 having side surfaces 302,303 and a bottom wall 304. Side surface 302 may be provided with double-faced tape 305, if desired. A circular bore 306 is provided through bottom wall 304 and intersects with side surface 303 whereby a concave, semicylindrical recess 307 is formed in side surface 303 of channel 301. The cylindrical recess 307 is sized so as to receive pressure unit 308. 
     Pressure unit 308, as seen in FIG. 8, comprises a semicylindrical cylindrical pressure block 309 having a vertical tapped bore 310, a transverse bore 311 intersecting with tapped bore 310, and a screw 312 disposed within tapped bore 310. A ball 313 is slidingly disposed within transverse bore 311 and is movable within the transverse bore 311 in response to the adjustment of screw 312. 
     The assembly of the preferred embodiment, as illustrated in FIGS. 9 and 10, is similar to that described above. As seen in the Figures, a glass panel 314 is positioned within channel 301 and against the double-faced tape 305 on the side surface 302. The pressure block 309 is then inserted through circular bore 306 into semicylindrical recess 307. Screw 312 is then adjusted to move ball 313 outwardly, whereby glass panel 314 is secured within channel 301. 
     In the preferred embodiment just described, it can be seen that the structural integrity of the side surface 303 of the shoe 300 is maintained, even in the presence of a thick glass panel, by providing only a localized recess in the side surface to accomodate the pressure unit 309. In the case of a thinner glass panel, the position of circular bore 306 is moved toward the center of channel 301 so that pressure unit 308 is in the proper position to secure the glass panel in place. 
     Although not illustrated, it is to be understood that the preferred embodiment of the invention may also be provided with adjustment screws, such as screws 23 in FIGS. 2 and 3, to square the glass panel with the shoe. 
     As the foregoing description illustrates, the invention provides a new and useful glazing system for metal frame and glass panel structures wherein the use of at least two independent expandable pressure units within a channel of the frame securely retain the glass panel within the frame without creating excessive stresses in the glass panel which would otherwise make the glass panel more susceptible to breakage. 
     Preferred forms of the invention have been described and shown herein for purposes of illustration only and not for purposes of limitation, and various modifications or alterations may suggest themselves to those skilled in the art, all of which are within the scope of the invention as defined in the appended claims.