Abstract:
Locking mechanisms for backrest portions of (typically vehicle) seats are detailed. The mechanisms avoid any need to use conventional recline locks and thus simplify the designs of existing seats otherwise so equipped. The mechanisms also permit adjustment of the positions of the backrests relative to the bases prior to deployment and allow for tolerances as well.

Description:
FIELD OF THE INVENTION  
         [0001]    This invention relates to locking mechanisms for seats and more particularly (although not exclusively) to assemblies for preventing backs of vehicle seats from reclining.  
         BACKGROUND OF THE INVENTION  
         [0002]    U.S. Pat. No. 5,133,587 to Hadden, Jr., incorporated herein in its entirety by this reference, discusses certain conventional vehicle seats. The seats include “upper pivotable back portions” and “lower stationary seating portions” attached together using pivot bolts. Typically by depressing buttons in armrests of the seats, users may actuate hydrolock mechanisms and cause the back portions to pivot between upright and various reclined positions.  
           [0003]    U.S. Pat. No. 6,328,382 to Yawashita, likewise incorporated herein in its entirety by this reference, details a locking structure for a reclinable seat. The seat includes a back and a base (denominated a “cushion”), each having a bracket secured to it. A pair of lock gears is interposed between the brackets and operated by a rotatable cam when a passenger moves a lever or handle.  
           [0004]    Common carriers, such as passenger airlines, bus lines, and train lines, frequently convey substantial numbers of passengers simultaneously. Fleet vehicles of these carriers thus typically contain multiple passenger seats, some or many of which, like the seats of the Hadden, Jr. and Yawashita patents, are adapted to recline. Moreover, in a particular accommodation class within a passenger vehicle, carriers often strive for uniformity of seating for reasons of cost, safety, aesthetics, and fairness. In many instances, therefore, standard seats produced for common carriers usually are designed to be reclinable upon passenger demand.  
           [0005]    Notwithstanding the foregoing, however, some seats within certain vehicles advantageously do not recline. One example of such seats are those in rows of seating immediately forward of commercial aircraft exits. If these seats could recline, then seatbacks could impede passengers from escaping from aircraft exits during emergencies. Similarly, seats positioned immediately forward of bulkheads, galleys, lavatories, or other parts of commercial vehicles need not recline. Other seats, while not having their backrests fixed in a fully-upright position, nevertheless beneficially may not permit customer adjustment in use.  
         SUMMARY OF THE INVENTION  
         [0006]    The present invention provides mechanisms for preventing vehicle seats from reclining. The mechanisms, further, simplify the designs of existing seats whose ability to recline has been inhibited, typically with devices known in the art as “recline locks” or “hydrolocks.” They thus provide relatively low-cost, low-maintenance alternatives to existing recline-impeding assemblies.  
           [0007]    Preferred embodiments of the mechanisms of the present invention include a support back and retaining bushing forming an interface between the spreader assemblies (bases) and backrest portions of seats. Incorporated into support backs are serrations and slotted openings. Together with serrations present on the bushings, the serrations and slots of the support backs permit initial adjustment of the positions of the backrests relative to the bases (and allow for tolerances as well). Stated differently, the backrests may be locked in positions other than fully upright prior to deployment in vehicles.  
           [0008]    It thus is an optional, non-exclusive object of the present invention to provide seats including recline-inhibiting mechanisms.  
           [0009]    It is an additional optional, non-exclusive object of the present invention to provide vehicle seats whose backrest portions are fixed relative to the bases after deployment in vehicles.  
           [0010]    It is a further optional, non-exclusive object of the present invention to provide seats omitting conventional recline locks (or hydrolocks) in favor of simplified designs.  
           [0011]    It is also an optional, non-exclusive object of the present invention to provide seat-locking mechanisms including support backs and bushings.  
           [0012]    It is another optional, non-exclusive object of the present invention to provide seats in which slots and serrations in support backs or bushings permit adjustment (and allow for tolerances) prior to deployment.  
           [0013]    Other objects, features, and advantages of the present invention will be apparent to those skilled in the relevant fields with reference to the remaining text and drawings of this application.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]    [0014]FIG. 1 is a perspective view of a (nominally) interior face of an exemplary support back of the present invention.  
         [0015]    [0015]FIG. 2 is a perspective view of a (nominally) exterior face of the support back of FIG. 1.  
         [0016]    [0016]FIG. 3 is a perspective view of an exemplary bushing of the present invention.  
         [0017]    [0017]FIG. 4 illustrates the support back of FIG. 1 attached to a seat.  
         [0018]    [0018]FIG. 5 illustrates the support back of FIG. 1 and the bushing of FIG. 3 attached to a seat. 
     
    
     DETAILED DESCRIPTION  
       [0019]    [0019]FIGS. 1-2 depict support back  10  of the present invention. Together with bushing  14  shown in FIG. 3 (and appropriate fasteners), support back  10  comprises a mechanism for fixing the position of the backrest portion of a seat relative to its base. Such mechanism (labelled  18 ) is illustrated in FIG. 5 installed in seat S, some of whose exterior components have been removed to facilitate viewing of its frame. One such seat S preferably is structured like that in FIGS. 1-3 of the Hadden, Jr. patent (albeit without need for the hydrolock depicted therein), although mechanism  18  alternatively may be used with other types of seats.  
         [0020]    As detailed in FIGS. 1-2, support back  10  may be a cast, irregularly-shaped component, typically formed of metal or composite materials. Support back  10  contains multiple spaced openings  22 ,  26 , and  30  adapted to receive bolts or other suitable fasteners. Openings  22  and  26  preferably have circular cross-section, while opening  30  preferably is elongated and thus in the nature of a slot (with generally elliptical cross-section). Support back  10  further may include recess  34  of exterior face  36 , whose existence corresponds with shoulder  38  of interior face  40 , and arm  42  formed with (or otherwise connected to) its main body  46 .  
         [0021]    Also depicted as included on exterior face  36  are serrations  50 . Such serrations  50  are associated with elongated opening  30 , although they need not necessarily uniformly surround the opening  30  as shown in FIG. 2. In use, serrations  50  engage corresponding serrations  54  of bushing  14  (FIG. 3), so that movement of support back  10  and bushing  14  cannot thereafter occur. Further, because serrations  50  surround the length of opening  30 , bushing  14  may engage support back  10  anywhere in the serrated region, thus allowing its position relative to support back  10  to vary prior to tightening of the associated fastener. (Or, described differently, any fastener passing through opening  58  of bushing  14  need not pass through the center of elongated opening  30 , but rather may pass through any portion of the opening  30 .) This variable positioning allows the backrest to be reclined a selected amount before its position is fixed. Applicants note, however, that those skilled in the art will recognize that engagement mechanisms other than serrations  50  and  54  may be utilized instead yet achieve the desired results.  
         [0022]    [0022]FIG. 4 illustrates support back  10  positioned for attachment to seat S. As shown in FIG. 4, connection of support back  10  to base  62  of seat S may occur by inserting bolt  66  or other appropriate fastener through opening  22  and an aligned opening of base  62 . An additional fastener may be inserted through opening  26  for connection to a recessed portion of base  62 . With support back  10  so connected, a bolt or part of another suitable fastening assembly  68  may be inserted through opening  58  of bushing  14 , (elongated) opening  30  of support back  10 , and through an aligned opening of backrest portion  70  of seat S. This connection, at the pivot axis of backrest portion  70 , prevents portion  70  from pivoting following engagement of serrations  50  and  54  and tightening of the fastener.  
         [0023]    If desired, an additional mechanism  18  may be connected similarly on the opposite side of seat S. Doing so distributes forces otherwise present solely on the mechanism  18  depicted in FIG. 5 and thus is preferred when mechanism  18  is used with a vehicle seat. Moreover, in certain situations mechanism  18  could be used together with a recline lock or hydrolock, although doing so is unnecessary in the context of the invention.  
         [0024]    The foregoing is provided for purposes of illustrating, explaining, and describing exemplary embodiments and certain benefits of the present invention. Modifications and adaptations to the illustrated and described embodiments will be apparent to those skilled in the relevant art and may be made without departing from the scope or spirit of the invention.