Abstract:
A mounting mechanism is provided for attaching a diffuser to a fluorescent lighting fixture. The mounting mechanism is coupled to the diffuser and includes an elongated latch member and an elongated second member. Each member of the mechanism is pivotally coupled to an end of the diffuser in a spaced apart relationship. The members are coupled to each other via a spring connected to each member below the member&#39;s pivotal point. The second member may also be a latch member of may be a hinge member. Each latch member penetrates a notch formed through the housing socket plate and latches on an upper surface of the socket plate. Each hinge member includes a hook portion having a tip. The hook portion penetrates a first notch formed on the socket plate in a first direction while the tip portion penetrates a second opening adjacent the first opening in a second direction opposite the first direction thereby hooking on the socket plate.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority and is based on Provisional Application No. 60/129,005, filed Apr. 13, 1999, and fully incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to mounting mechanisms and specifically to mechanisms for mounting diffusers to fluorescent lighting fixtures. 
     BACKGROUND OF THE INVENTION 
     Fluorescent lighting fixtures typically have a plastic diffuser (i.e., lens) attached to the fixture housing so as to enclose the fluorescent lighting tubes and to diffuse the light in the most advantageous manner. When the diffuser is in place, the fluorescent lighting tubes, ballast, fixture wires as well as any starter units, are entirely enclosed within the fixture. These fixtures are normally provided with mounting mechanisms for mounting the diffuser to the housing. Typically a mounting mechanism is attached at each end of the diffuser. A mounting mechanism consists of a pair hinges pivotally mounted in a spaced apart relationship at an end of the diffuser. The bottoms of the hinges are coupled to each other via a spring. A hook extends from the top portions of the hinges. 
     The problem with current hooked hinges is that they sometimes “hook” onto wires located in the housing making disengagement of the hooks from the housing difficult. Moreover, sometimes the fixture wires block the upward movement of the hooks preventing them from disengaging from the openings. Furthermore, hooks hook onto the socket plate and as consequence require that the diffuser is lifted during dismounting to free the hooks from the socket plate. As such, a mechanism is desired that would allow for easy mounting and dismounting of the diffuser from the fixture housing, preclude the hooking of any wires in the housing and eliminate the requirement of lifting of the diffuser for complete dismounting. 
     SUMMARY OF THE INVENTION 
     Accordingly, the present invention provides a mounting apparatus for attaching a diffuser to a fluorescent lighting fixture so that the diffuser may be easily removed entirely from the housing or may be hinged along a longitudinal axis of the housing providing access to the enclosed components. When hinged, the present invention provides means for preventing the diffuser from being accidentally disengaged from the housing when in the open position. 
     In one embodiment, the present invention provides a combination latch and hinge mounting mechanism which is simple in operation and economical in construction. In an alternate embodiment, the present invention provides a latch and latch mechanism. The latches in this mechanism engage the socket plates of a fixture without hooking on to them. Consequently, lifting of the diffuser is not required for disengaging the latches. 
     These and other attendant advantages of this invention will be readily appreciated as the same become better understood by reference to the following detailed description considered in connection with the accompanying drawings. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     FIG. 1A is a front sectional view of a hinge mounting mechanism with the diffuser secured in an intermediate position on a fluorescent fixture according to the prior art. 
     FIG. 1B is a front sectional view of the hinge mounting mechanism with diffuser shown in FIG. 1A secured in a fully mounted position. 
     FIG. 2 is a plan view of a socket plate. 
     FIG. 3 is a front sectional view of the mechanism of FIG. 1 with the diffuser lifted in an intermediate position. 
     FIG. 4A is a side view of an elongated latch member. 
     FIG. 4B is a side view of another embodiment elongated latch member. 
     FIG. 4C is a side view of another embodiment elongated latch member. 
     FIG. 5A is a front sectional view of a mounting mechanism of the present invention with the diffuser secured in an intermediate position on the fluorescent fixture. 
     FIG. 5B is a front sectional view of the mounting mechanism shown in FIG. 5A, with latch member of the apparatus moved to a position for disengagement. 
     FIG. 5C is a front sectional view of another embodiment mounting mechanism of the present invention comprising two latches. 
     FIG. 5D is a front sectional view of the mounting mechanism of FIG. 5A, with the latch disengaged and the diffuser hinged away from the fixture. 
     FIG. 6 is a side view of a hinge or hooked latch member of the present invention. 
     FIG. 7 is a front sectional view of another embodiment mounting mechanism of the present invention comprising a hooked latch member and a hinge. 
     FIG. 8 is a front sectional view of an alternate embodiment mounting mechanism of the present invention comprising two hooked latch members. 
     FIG. 9 is a front sectional view of an alternate embodiment mounting mechanism of the present invention comprising a latch member and a hooked latch member. 
     FIG. 10 is a front sectional view of an alternate embodiment mounting mechanism coupled to the fixture housing and engaging the diffuser. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The prior art diffuser mounting or hinge mechanisms (i.e., apparatus) consist of two spaced apart hinges  10 , each pivotally mounted on an end of the diffuser  12  (FIG.  1 A). Each prior art mechanism consists of a spring  14  coupled to the bottom portions  16  of the two hinges below their pivoting points  18 . A hook  15  is formed at the upper end of each hinge in each mechanism. The two hinge hooks within each mechanism face outwardly away from each other. Moreover, a notch  19 , referred to herein for convenience as a lock notch, is formed on the external edge  21  of each hinge above the pivot point  18  of each hinge. A mounting mechanism is attached to each end of the diffuser. Consequently, the hinges of each mounting mechanism are pivotally mounted to an end of a diffuser. 
     To mount the diffuser onto the fixture housing, the top portions of the hinges of each mechanism are pushed toward each other (i.e., the bottom portions are moved outward) so as to pivot the hinges to a position to allow the hooks of the hinges to be fitted through corresponding slots  20  formed on the fixture housing socket plates  27  (FIG. 2) by lifting the diffuser upward toward the fixture. The top portions  26  of the hinges are then allowed to pivot away from each other by the force of the spring pulling the bottom portions of the hinges toward each other causing the tips  22  of the hooks to extend over openings  24  formed adjacent to the slots  20  on the socket plate. A bridge  25  is defined between the slot  20  and adjacent opening  24 . The tips of the hooks penetrate these openings as the diffuser is allowed to drop. Consequently, the hooks hook around the bridge, thereby hooking the diffuser to the socket plate and thus the housing as shown in FIG.  1 . The diffuser is then pushed upward. As the diffuser continues upward the spring  4  urges the lower portions of the hinges within each mechanism toward each other and the diffuser is secured against the fixture housing when the lock notch  19  at each hinge engages an edge  23  of its corresponding slot  20  as shown in FIG.  1 B. 
     To dismount the diffuser, the diffuser is pulled downward forcing the upper portions of the hinges toward each other as the notches  19  on the hinges slide past the slot edges  23 . The hooks of the hinges then hook around their corresponding bridges  25  on the socket plate. To fully dismount the diffuser, the diffuser is lifted so as to disengage the hook tips from the openings  24 . The top portions  26  of the hinges are then moved toward each other orienting the hinges with their corresponding slots  20  as shown in FIG.  3 . The hook  15  of each hinge is then allowed to fall through its corresponding slot  20  in the socket plate. Lifting the diffuser causes a wider part of the hinge to penetrate the slot making it more difficult to rotate the top portions of the hinges toward each other. 
     With the prior art hinge mechanisms, the fixture wires  30  running from the ballast to the sockets  31  often impede or prevent the hinge from achieving the required vertical position for disengagement. Moreover, during installation or removal of the diffuser, the hooks many times hook on the wires making removal of the diffuser difficult. Furthermore, the hooked wires may prevent the hook tips  22  from penetrating the openings  24  formed adjacent to the slots for properly “hooking” onto the bridge  25 . In addition, the diffuser must be lifted to fully disengage the hooks from the socket plate. 
     The mounting systems of the present inventions overcome these problems. In a first embodiment, an improvement over the prior art mechanisms is provided by using a latch  40  instead of a hinge in each mechanism (FIG.  4 A). If one latch is used in each mechanism at each end of the diffuser, the latches should be oriented along the same side of the diffuser. 
     It should be noted that the terms “upper”, “lower”, “top”, and “bottom” are used as relative terms throughout the specification for conveniently distinguishing various elements of the invention and are not meant to denote the actual spatial position of the elements. For example, an upper portion may be located below a lower portion. 
     The inventive latch comprises a neck portion  42  from which extends a head  44  having a relatively flat bottom edge  46  that intersects an edge  48  of the neck. The neck is narrower than the body  52  of the latch. The head  44  and its bottom edge  46  bottom edge extend transversely beyond the neck  42 . The head bottom edge  46  is preferably approximately perpendicular to the edge  48  of the neck. In a preferred embodiment, the head bottom edge is also approximately perpendicular to the latch central longitudinal axis  49 . However, the angle  50  from the relatively flat bottom edge  46  of the head to the longitudinal axis  49  as measured away from the head  44  can be any angle not less than 90° and less than 180°. In this regard, a hook is not created between the head and the neck which can accidentally hook on the fixture wires. 
     Another embodiment latch is shown in FIG.  4 B. With this embodiment latch, the head  64  has a relatively bottom edge  66  which forms an angle  65  greater than 90° with the longitudinal axis  69  of the latch. A neck portion  62  is defined below the head portion  64 . The angle  71  from head bottom edge  66  to the neck edge  68  as measured away from the head  64  is also greater than 90°. A yet further embodiment latch is shown in FIG.  4 C. This embodiment latch member consists of a notch  78  on the upper portion of the latch member. A head  74  having a relatively flat bottom edge  76  is defined over the notch  78  such that the notch upper edge  75  defines the bottom edge  76  of the head  74 . A neck portion  72  is defined below the bottom edge  76 . The angle  77  from the notch bottom edge  76  and the central axis  79  of the latch as measured away from the head  74  is not less than 900. In preferred embodiments, the bottom edges  46 ,  66  and  76  of the heads are substantially flat. 
     To engage the latch to the fixture, the latch is rotated to align the head  44 ,  64 ,  74  with a corresponding slot  20  on the socket plate  27  of the housing fixture. The head  44 ,  64 ,  74  is then moved through the slot in the fixture by lifting the diffuser toward the fixture. The latch is then released and the spring force rotates the latch as for example shown by arrow  51  in FIG. 5A such that the neck  42 ,  62 ,  72  moves across the slot  20  such that the bottom edge  46  of the head engages the upper surface  29  of the socket plate  27  (FIG.  5 A). The spring force causes the head to maintain engagement with the fixture. The diffuser is then lifted to its final installed position where the lock notch  19  formed on each latch member upper portion engages the bridge  25  on the socket plate so as to lock the diffuser onto the housing. 
     Because, the head  44 ,  64 ,  74  of the latch does not form a hook, it will not hook on the fixture wires  15 . If the head were to engage the wires, disengagement can be easily accomplished by pivoting the head as necessary. While for proper functioning the latch only requires that a single slot or opening, e.g., slot  20 , is formed on the socket plate of the fixture, the latch can be used with existing socket plates which have an opening  24  adjacent to each slot such as opening  24  shown in FIG.  2 . In such cases, at least a portion of the bottom edge  46 ,  66 ,  76  of the latch head will seat on the top surface of the bridge  25  formed between the slot and the opening and will not penetrate the opening adjacent to the slot as shown in FIG.  5 A. As a result, the latch would not “hook” on the fixture socket plate  27 . Consequently, the latch can be easily released from the fixture by pushing the upper portion  73  of the latch inward as shown by arrow  53  in FIG. 5B until the head is aligned with its corresponding slot  20 . The head is then allowed to fall through its corresponding slot. In this regard, the diffuser does not have to be lifted to disengage the latch. 
     The mounting mechanism of the present invention may comprise a latch and a hinge  80  as shown in FIG.  5 A. The hinge has a hook portion  82  extending from its upper end (FIG.  6 ). When used with conventional fixture housings, the hook portion hooks on the bridge  25  formed on the socket plates of the fixture between the slot  20  and an opening  24 . The latch of each mechanism at either end of the diffuser may be easily disengaged from the housing by pushing the latch upper portions  73  toward their corresponding hinges as shown by arrow  53  in FIG. 5B so as to bring their heads over their corresponding slots  20  on the fixture socket plate. The heads are allowed to drop through their corresponding slots. By coupling the latches on the same side of each diffuser head, disengagement of the latches will disengage that side of the diffuser from the fixture. The other side of the diffuser will remain hooked on the diffuser by the hinges  80  as shown in FIG.  5 D. In this regard, access is provided to the fluorescent tubes, ballast and wiring without completely removing the diffuser. Moreover, reinstallation of the diffuser only requires that the latches are rotated so that their heads can penetrate their corresponding slots. 
     To prevent accidental disengagement of the hook  82  of the hinge  80  from the socket plate, the hook  82  forms a channel  83  (as shown in FIG.6) for snugly accommodating a bridge  25  of the socket plate. The hook has an outwardly extending portion  84 . A downward portion  86  extends from the end of the outwardly extending portion. A return  85  extends from the end of the downward portion. The inner edges of the outward, downward and return portions define the channel  83 . The inner edge  88  of the return is flat for interfacing with the lower surface of the bridge  25 . The inner edge  89  of the downward portion is also flat and perpendicular with the inner edge  88  of the return for interfacing with the edge of the bridge defined by the opening  24 . The inner edge  90  of the outwardly extending portion is curved for engaging a portion of the bridge upper surface. Once the bridge is engaged by the three edges, rotation of the hook is prevented in an inward direction, i.e., the direction that the weight of the diffuser would attempt to rotate the hook when only one side of the diffuser is hingeably hanging from the housing as shown for example in FIG.  5 D. 
     In an alternate embodiment, a mounting mechanism may incorporate two latches simplifying the mounting and removal of the diffuser (FIG. 5 C). With this embodiment, the heads of the latches extend opposite each other in an outwardly direction. 
     In a further embodiment mounting mechanism, a hooked latch member is used having a hook extending from its upper end instead of a head. This member can be the same as the hinge member  80  shown in FIG.  6 . To allow the hooked member  90  to act as a latch, a single slot or opening (e.g., slot  20 ) is formed on the socket plate corresponding to the hooked latch. If an opening exists adjacent to the slot it may have to be plugged as necessary to prevent the hook latch from hooking onto the socket plate. To attach the diffuser to the housing, the member is rotated against the spring force so that its hook is aligned with the slot  20  (or opening). The hook is moved through the slot  20  on the fixture socket plate  27 . The member is then released causing the hook to rotate outward and the tip of the hook to move over and engage the upper surface  94  of the fixture socket plate as shown in FIG.  7 . The hook tip return  85  should have a lower edge  96  for resting flat against the upper surface of the socket plate when in a locking position. In a preferred embodiment, the hook tip has a flat lower edge  96  approximately perpendicular to the member longitudinal axis for engaging the upper surface  94  of the socket plate. In alternate embodiments, a mounting mechanism may incorporate a pair of hooked latches (FIG.  8 ), or may incorporate a latch and a hooked latch (FIG.  9 ), or a hinge and a hooked latch (FIG.  7 ). 
     For convenience, the present invention diffuser mounting mechanisms have been described for engaging a socket plate at each end of the fixture. However, the present invention mounting mechanisms are not limited to use with socket plates at each end of the fixture. For example, all the mounting mechanisms of a diffuser can latch or hook on to a single plate spanning a portion or the entire fixture or they can latch or hook onto a bracket or multiple brackets or to a wall connected to or integral the fixture. As such, the term “socket plate” as used herein should be construed to mean any structure connected or integral to the fixture onto which the mounting mechanisms of the present invention can latch and/or hook upon. 
     In alternate embodiments, the hook and/or latch members described herein are pivotally coupled to the fixture housing  8  as shown in FIG.  10  and engage the diffusers. With these embodiments, the diffuser is provided with a plate structure  92  that has openings to accommodate the members.