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FIELD OF THE INVENTION  
       [0001]     The invention is directed toward the field of suspended ceiling systems, particularly to torsion spring attachment systems, and more particularly to a clip and frame assembly for torsion spring attachment.  
       BACKGROUND OF THE INVENTION  
       [0002]     Suspended acoustical ceiling systems are frequently used to mask functional systems such as plumbing, electrical wiring, telecommunications wiring and the like. There are two basic types of suspended acoustical ceiling systems: lay-in panel systems, in which the ceiling tiles are lifted into and rest on a metal grid suspension system with no physical attachment; and frame panel systems in which each of the tiles is surrounded by a rigid frame that is, in turn, connected securely to a metal grid.  
         [0003]      FIG. 1  depicts a typical suspended ceiling system  100  of the frame panel type comprising plurality of ceiling panels  102  that are supported by and removably attached to a suspended grid  104 . Torsion springs  112  are attached to each panel  102  and provide a removable means for holding the panel securely against a foot portion  104   a  of the grid  104 . As illustrated in  FIG. 1 , one panel, panel  102   a,  is depicted in an open and partially disconnected orientation in which two of the torsion springs  112   a  have been partially disengaged from the corresponding grid clips  106 , allowing the panel  102   a  to be lowered relative to the grid  104 , and the other two torsion springs  112  have been completely disconnected from their corresponding grid clips (not shown), allowing the panel to be rotated away from the grid to provide access to the space above the suspended ceiling. The torsion springs  112  are typically attached to the individual panels using a series of panel clips  110  (not shown) that are attached to the metal frame  108  at appropriate points around the edge of the metal frame.  
         [0004]      FIG. 2  illustrates in more detail the construction and configuration of the various mechanical elements in a conventional frame type panel system according to  FIG. 1 . As illustrated in  FIG. 2 , the support grid may be formed from a plurality of T-bars  250 , each of which may include a foot flange  253 , a web  251  and a bead portion  254 . Grid clips  230  may be provided on or attached to the bead  254  using a releasable fastener, such as screw  240 . As illustrated, each grid clip  230  includes a U-shaped channel  232  and an opposed pair of projecting flanges  234  in which a slot  236  is provided.  
         [0005]     The arms  218  of the torsional springs  214  are arranged and configured to fit into the slot  236  and provide a frictional fit sufficient to hold the panel  200  in place against the foot flange  253  when the panel is in the installed position. The arms  218  of the torsional spring  214  may also be provided with retaining feet  220  or other structures that are arranged and configured to rest against an upper surface of the projecting flange  234  for suspending the panel when lowered into a disengaged position below the grid. The arms  218  of the torsional spring  214  may also be arranged and configured so that they may be manually deflected to release the engagement between the retaining feet  220  and the projecting flange  234  and allow the panel or one side of the panel to be completely detached from the grid.  
         [0006]     Each framed panel  200  includes a frame  226  formed around the outer edge of the tile  228 . The framed panel  200  may include an optional cover  210  of fabric or other suitable materials. A frame clip  212  fits onto a flange provided on the frame  226  and provides a raised hook portion that is configured fit through the wound portion  216  of the torsional spring  214  and thereby suspend the panel from the torsional spring.  
         [0007]     To fit the framed panel  200  against the T-bars  250 , the arms  218  of the torsion spring  214  are pushed up through the slot  236  resulting in the arms  218  spreading out in a v-shape. Consequently, the frame  226  (or the fabric  210 ) will bear against the foot portion  253  of the T-bar. To assist in aligning adjacent panels, an optional alignment clip  290  can be attached to the T-bar  250 .  
       SUMMARY OF THE INVENTION  
       [0008]     Exemplary embodiments of the present invention provide an improved frame clip arranged and configured to be easily field-mounted and/or easily reconfigured on a panel frame. The ease with which the frame clip may be attached to a panel frame without contacting the panel tile allows the panels to be shipped without frame clips and/or torsion springs, thereby simplifying the packaging and reducing the likelihood of shipping damage resulting from projecting edges.  
         [0009]     The improved frame clip also provides a locking function for securing the wound portion of a torsion spring or other attachment means to a panel frame as the frame clip is secured. This locking function simplifies panel installation and removal by ensuring that the torsion springs are not dislodged as a result of panel movement and reducing the likelihood that a panel will drop unexpectedly while being handled.  
         [0010]     The improved frame clip may be attached to the panel frame using a variety of fastening means. For example, the channel wall of the panel frame may be provided with a groove or other indents centered opposite the channel opening to aid in the attachment of the frame clip using self-drilling fasteners. Similarly, the receiving portion of the panel frame can be provided with holes for self-tapping fasteners or may contain a nut or other element for receiving the forward portion of a fastener. The panel frame may also be provided with notches, detents or other positioning indicia to improve the ability of an installer to position the frame clip accurately and repeatedly. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]     The accompanying drawings are intended to depict exemplary embodiments of the invention to aid those of ordinary skill in the art in understanding the present invention and should not be interpreted in such as manner as to limit the scope of the present invention to the illustrated embodiments. Similarly, the accompanying drawings are not, unless explicitly noted, drawn to scale and should not be interpreted in a manner that limits the size, spacing or relative dimensions of the illustrated mechanical elements.  
         [0012]      FIG. 1  is a three-quarter perspective drawing of a conventional suspended ceiling system utilizing torsion spring attachments;  
         [0013]      FIG. 2  is a more detailed view of a conventional torsion spring attachment system suitable for use in the suspended ceiling system illustrated in  FIG. 1 ;  
         [0014]     FIGS.  3 A-C are plan, side and front views of a frame clip according to an exemplary embodiment of the present invention;  
         [0015]      FIG. 4  provides a three-quarter view of a panel frame according to an exemplary embodiment of the invention;  
         [0016]     FIGS.  5 A-D are a sequence of views illustrating the insertion and mounting of a frame clip as illustrated in FIGS.  3 A-C into a corresponding panel frame according generally to  FIG. 4 ;  
         [0017]     FIGS.  6 A-C are views illustrating exemplary embodiments of frame clips utilizing various exemplary hook configurations;  
         [0018]     FIGS.  7 A-C are views illustrating exemplary combinations of frame clip inserts and corresponding panel frame channel configurations;  
         [0019]      FIG. 8  illustrates the mechanical relationship of certain structural elements of a frame clip according generally to  FIG. 3A  when installed in a panel frame generally according to  FIG. 4  to form an exemplary embodiment of the present invention;  
         [0020]      FIG. 9  illustrates a range of motion for a captive torsion spring attached to a panel frame using a frame clip according to an exemplary embodiment of the invention;  
         [0021]      FIGS. 10A and 10B  provide a plan view of the action of a parallelogram nut suitable for use in combination with a frame clip and frame according to exemplary embodiments of the present invention; and  
         [0022]      FIGS. 11A and 11B  provide a side view of a parallelogram nut according to  FIGS. 10A and 10B  being used in combination with an exemplary frame clip, frame and fastener in accord with the present invention. 
     
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS  
       [0023]     As illustrated in FIGS.  3 A-C, an exemplary frame clip  10  according to the present invention includes a main body  12  that includes a top surface  14 , a bottom surface  16 , a first length  18  and a first width  20  and is generally planar. The frame clip  10  also includes an insert  22  that has an upper surface  24 , a lower surface  26 , a second length  28  and a second width  30  and, like the main body, is generally planar but is offset from the main body  12  by an offset depth  32  and an offset length  34 . The frame clip  10  also includes a neck  36  that connects the main body  12  and the insert  22  and maintains their relative parallel and spaced apart orientation. The frame clip  10  also defines a longitudinal axis and may be generally symmetrical about the axis.  
         [0024]     The frame clip  10  also includes a hook  38  extending above the main body  12  that includes a free forward portion  40  and is attached to the main body of the frame clip at a rear portion  42 . The hook  38  is typically oriented in a plane generally perpendicular to both the plane defined by the main body  12  and the longitudinal axis of the frame clip  10 , but depending on the particular application, other orientations may be utilized. The forward portion  40  of the hook may extend downwardly to a point generally adjacent a plane defined by the bottom surface  16  of the main body  12  or by an upper surface of a frame to which the frame clip is attached.  
         [0025]     The forward portion  40  of the hook  38  is also set apart from the main body by a distance sufficient to allow the wound portion  44  of a torsion spring  46  to be placed on the hook without interference from the main body  12 . Depending on the location of the forward portion  40  of the hook  38 , a notch or recess  48  may be provided at a corresponding edge in the main body  12  of the frame clip  10  to ensure sufficient spacing is available. The frame clip  10  may also include one or more openings  65  arranged on one or both sides of the hook  38  through which a fastener may be inserted to secure the frame clip to a panel frame.  
         [0026]     As illustrated in  FIG. 4 , the frame clip  10  is arranged and configured to be used with a corresponding frame  52 . The frame  52  may be constructed of a metal, such as aluminum or an alloy, or a polymeric material that may include reinforcing materials. The frame may be formed by extrusion, pultrusion, machining or casting depending on the material(s) used and the intended application, but a conventional aluminum extrusion will generally be satisfactory. The frame  52  includes a channel  54  into which the insert  22  will fit, the channel having an inner periphery, inner shoulder surfaces  56 , outer shoulder surfaces  58 , a rear wall  60 , a longitudinal opening  62  and a longitudinal channel axis. The frame  52  may also include a groove, notch or other structures on the rear wall  60  of the channel  52  to improve the ease with which self-tapping or self-drilling fasteners may be inserted into the rear wall. The frame  52  will also typically be provided with another channel, slot or projections  68  arranged and configured to receive and support a ceiling tile or similar object within a completed panel frame.  
         [0027]     FIGS.  5 A-D illustrate a method of attaching a frame clip  10  to a corresponding frame  52 . As illustrated in  FIG. 5A , the thickness of the frame clip  10  is smaller than the opening  62  into the channel  54  provided in the frame  52 , thereby allowing the frame clip to be appropriately oriented with the insert  22  positioned in the channel. As illustrated in  FIG. 5B , the frame clip  10  can then be rotated generally about a longitudinal axis so that the insert  22 , which is preferably configured to have an outer periphery generally corresponding to, but slightly smaller than, at least portions of the inner periphery of the channel  54  will be held in the channel. Similarly, the neck  36  of the frame clip  10  is typically configured to have a maximum width slightly smaller than the width of opening  62  so that the frame clip can be rotated without binding on the sides of the opening. As illustrated in  FIG. 5B , the insert  22  is configured to be wider than the opening  62  into the channel so that when the plane of the frame clip  10  is substantially perpendicular to the longitudinal channel axis, attempting to remove the frame clip from the channel causes the insert to contact the inner shoulder surfaces  56  of the frame  52  and thereby tend to retain the insert within the channel.  
         [0028]     As illustrated in  FIG. 5C , a torsion spring  46  can then be slipped over the free forward portion  40  of the hook  38  provided on the frame clip  10 . As illustrated in  FIG. 5D , the frame clip  10  can then be rotated about a transverse axis positioned near or extending through the neck  36  portion. The repositioning of the frame clip  10  typically establishes contact between the bottom surface  16  of the main body  12  and the outer shoulder surfaces  58  of the frame  52  as well as between the upper surface of the insert  24  and the inner shoulder surfaces. The forward portion  40  of the hook  38  will also be moved adjacent a portion of the frame  52  to secure the torsion spring on the hook  38  as the frame clip is rotated to its installed position. Once the frame clip  10  is appropriately positioned, a fastener such as a screw  64  can be attached to the frame through a portion of the frame clip. One or more holes  65  or thinned portions may be provided in the main body  12  of the frame clip to assist in the insertion of an appropriate fastener.  
         [0029]     As illustrated in the FIGS.  6 A-C, the hook  38  may be positioned in a number of orientations relative to the main body  12  of the frame clip  10 . A preferred embodiment is illustrated in  FIG. 6A  in which the hook  38  is provided generally within the periphery of the main body  12  with a notch or recess being provided in the main body to ensure sufficient clearance to allow a torsion spring or other structure to be placed on the hook. As illustrated in  FIGS. 6B and 6C , however, the forward portion  40  of the hook  38  can be extended well away from the main body  12 , provided there is other structure, such as a portion of the frame  52  that can interact with the forward portion of the hook to close the opening or at least decrease the width of the opening sufficiently to prevent a structure on the hook from being removed from the hook while the frame clip  10  is in its fully installed position.  
         [0030]     As illustrated in FIGS.  7 A-C, both the channel  54  provided in the frame  52  and the insert  22  of the frame clip  10  can assume a wide range of configurations. Further, although, as illustrated, the outer periphery of insert  22  and the inner periphery of the channel  54  are similar, those of ordinary skill in the art will appreciate that a wide range of shapes may be used successfully. Each of the range of configurations will, however, include an insert that is wider than the opening  62  and will contact the inner shoulder surfaces  56  of the channel if an attempt is made to remove the frame clip  10  without first rotating the frame clip to a position in which the upper surface of the insert is generally aligned with the longitudinal channel axis.  
         [0031]     As illustrated in  FIG. 8 , when installed the frame clip  10  will be positioned securely on the frame  52  to hold a torsion spring  46  or other connecting apparatus that will allow the panel, including a supported tile  70 , to be attached to a suspended grid. Typically a series of frame clips  10  will be located on the frame  52  with four or more sections of frame used to encompass and/or support the edges of a tile  70 , panel or other structural element. The use of frame clips  10  according to the present invention located along the sides of the frame sections allows the corners of the frames to be reinforced more strongly and may reduce or eliminate the need for gussets or other external reinforcing structures. This allows the basic panel frames to be assembled and shipped in a manner that reduces the likelihood of damage resulting from protruding structures and allows the installers to quickly install and position the necessary frame clips and supporting structures in the field.  
         [0032]     As illustrated in FIGS.  10 A-B, a preferred means of attaching an exemplary frame clip to the frame utilizes a nut  72  arranged and configured to allow insertion of the nut into the channel  54  through the opening  62  in one orientation and, by rotating the nut within the channel, to hold the nut within the channel and stop its rotation so that a fastener, such as a screw, can be tightened against the nut. As illustrated in FIGS.  11 A-B, the use of such a nut  72 , allows the combination of a frame clip  10 , fastener  64  and nut  72  sub-assembly  74 . With the nut  72  oriented appropriately, the sub-assembly  74  can then be inserted into the channel  54  as generally illustrated in FIGS.  5 A-D. Once the sub-assembly  74  is in place on the frame  52 , rotating the fastener  64  will cause the nut  72  to rotate and lock into the channel  54  and additional rotation of the fastener will cause the nut and the frame clip  10  to be securely attached to the shoulder portions of the channel. Although the illustrated nut  72  has a generally parallelogram shape, other configurations that allow the insertion of the nut through the channel opening and will contact the periphery of the channel when rotated to provide a “locking” function may be used in this manner. A self tapping screw may be used to secure the clip  10  to frame  52  without the use of nut  72 .  
         [0033]     The dimensions of the frame clip  10  may also be adjusted to provide an offset depth  32  that is slightly smaller than the thickness of the shoulder portions of the channel  54 . When the offset depth  32  is adjusted in this manner, some deformation of the main body  12 , insert  22  and/or of the neck  36  will occur as the frame clip  10  is being fastened to the frame  52  and provide a “locking” effect that will assist in maintaining the position of the frame clip as the fastener is rotated into a fully seated position. Similarly, the upper surface  24  of the insert  22  and/or the lower surface  16  of the main body  12  may be provided with projections or tabs that are configured to mate with corresponding detents or recesses in the frame  52  to help maintain the position of the frame clip  10  relative to the frame while the fastener  64  is being inserted and seated.  
         [0034]     Those of ordinary skill in the art will appreciate that the present invention may be embodied in forms other than those specifically illustrated and described herein departing from the spirit and essential characteristics of the invention. The exemplary embodiments of the invention described in detail above and illustrated in the accompanying figures are intended to aid in the understanding of the invention but should not be interpreted as unduly limiting the scope of the invention as defined in the appended claims. All changes which come within the meaning and equivalency of the claims are to be embraced.

Summary:
The present invention provides an improved frame clip arranged and constructed to be easily field-mounted and/or reconfigured on a panel frame such as those used to form suspended ceilings. By allowing the installation of the frame clips to be deferred until the panels are being installed, the frame clip permits the panels to be shipped without frame clips and/or attachment hardware, such as torsion springs, installed, thereby reducing the likelihood of shipping damage.