Abstract:
A frameless rail passenger seat having support members acting as sole support of the seat cushion frame and the seat back frame and being secured to the floor of a passenger rail car. The seat back frame is mounted on a pair of rotatably mounted shafts to allow the seat back to assume two opposing seat positions. A pair of link members are operatively connected to the pair of shafts and pivotally attached to the seat cushion frame, and have cam surfaces to engage a cam follower. Pins on the link members contact link members for support of one link member in each of the two seat positions.

Description:
[0001]    This application claims benefit of the filing date of provisional application, Ser. No. 60/284,985 filed Apr. 19, 2001. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    This invention relates in general to passenger seats and, in particular, to a frameless railcar passenger seat.  
           [0004]    2. Summary of the Prior Art  
           [0005]    Numerous designs for passenger seats have been used throughout the long history of railcars. A walkover seat is commonly used in passenger car applications because the seat position can be moved to oppositely facing directions. In previous designs, including those having a walkover seat back, the passenger seat commonly employs a seat frame to adequately support the structure. The use of seat frame in conjunction with a seat back frame and seat cushion requires a relatively heavy and expensive use of structural members, such as bars and cross members for adequate strength. Not only do such seat frames employ relatively heavy components, the installation of a seat frame in a passenger car contributes to installation time and costs. Moreover, the stresses applied to a seat frame must be absorbed by the frame structure.  
           [0006]    In its opposing positions, known seatbacks and seat cushion frames require latches, stops, and supports to retain the seat back. None of the prior techniques for retaining and moving the seat backs have not been wholly satisfactory due to installation and maintenance costs during use. Further, known designs suffer from problems in providing optimum seat support and activation of seat back movement with a satisfactory stop function. The previous designs are also not sufficiently heavy duty to support a seat in the absence of a seat frame. Therefore, it is desirable in the prior art to provide a car seat, which is simpler and more economical in design and installation, and provides smoother and more positive seat retention and support.  
         SUMMARY OF THE INVENTION  
         [0007]    It is, therefore, an objective of the invention to provide a frameless passenger railcar seat. It is further an objective of the invention to provide a cam assembly for supporting the seat structure and providing smooth and effective activation and retention of the seat back and cushion frame. The frameless seat of the invention employs a base support, which is attached directly to the floor of the passenger car. The design of the application eliminates the necessity of using heavy frame members to support the seat. The frameless design herein disclosed utilizes heavy-duty block and plate assemblies at each end to provide necessary structural support, whereby the railcar body is the stressed member. The design of the invention allows for efficient installation of the seat in the railcar and when installed, provides effective support of the seat with a lighter structure than in the prior art. The cam assembly of the passenger seat of the invention utilizes heavy-duty cam members, which insure positive activation of the seat back and contributes to the support and retention of seat structure in absence of the seat frame. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]    [0008]FIG. 1 is a front perspective view of the frameless passenger seat of the invention;  
         [0009]    [0009]FIG. 2 is an end elevational view, viewed outwardly, of the cam linkage assembly of the invention;  
         [0010]    [0010]FIG. 3 is a top perspective view of the end walkover shafts and cam linkage assembly of the frameless passenger seat of the invention;  
         [0011]    [0011]FIG. 4 is a top plan view of the frameless passenger seat of FIG. 1 with cushions removed; and  
         [0012]    [0012]FIG. 5 is a front elevational view of the frameless passenger seat of FIG. 4. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0013]    Referring now to FIGS.  1  to  5 , there is illustrated the improved frameless passenger seat of the invention, generally designated by reference numeral  2 . Although the frameless passenger seat is described herein as a seat for passenger railroad cars, it is within the scope of the invention to use the teachings of the invention in any environment in which passenger seats are employed. As is conventional, the passenger seat  2  includes a horizontal bench seat  4  and a seat back  6  as seen in FIG. 1. Although the seat back  6  is described herein as being of a walkover type allowing movement between two oppositely facing positions, it is within the scope of the invention to use the frameless design described herein in passenger seats not having a walkover capability.  
         [0014]    Referring now to FIGS. 4 and 5, the frameless support  10  of the railcar seat for solely supporting the horizontal bench seat  4  is best shown. A plate  12  is affixed to a lower hollow block support assembly  14  having a pair of vertical end walls  16 , an outer vertical wall  18  and an inward spaced wall  20  (FIG. 4). The block support assembly  14  is formed as a housing having a top horizontal wall  22  and bottom wall  24  for contacting the floor  25  of the passenger car. An angle member  26  having a lower horizontal plate or ledge  28  has a bottom surface  28   b  that contacts the wall  24  in overlapping relationship. The horizontal plate or ledge  28  includes a pair of holes (not shown) to receive respective mechanical fasteners  28   a  (FIG. 5), such as bolts and the like, to anchor the block assembly  14  and the angle member  26  to the floor  25  of the passenger seat car. A pair of vertical rods  34  are secured at their bottom ends  36  to the angle member  26  by welding or mechanical fasteners, and extend upward within the confines of the block assembly  14 . The upward end portion  38  of the rods  34  extend upward externally of the block housing into securement to the plate  12 . Although not intended to be so limited, the block assembly may be situated on an aisle side of the passenger seat  2 .  
         [0015]    The opposite side of the car seat  2  is supported on a vertical support in the form of a plate  50  having an angle member  52  secured thereto by bolts and the like and forming a bottom horizontal wall  54 . The bottom wall  54  includes holes  56  to receive bolts  52   a  and the like to secure the angle member  52  and the vertical plate  50  to the floor  32  of the railcar for support of the opposite side of the passenger seat  2 . Although the plate  50  and angle member  52  are shown as a single member, it is within the scope of the invention to use two support members.  
         [0016]    The seat back frame  60  is supported at each end by a pair of rotatably mounted walkover tubes  62   a  and  62   b . Solid end extensions  66   a  and  66   b  of walkover tubes  62   a ,  62   b  are respectively affixed to a pair of levers  68  extending upward and abutting each other in opposed seating positions of the seat back frame  69 . The abutting seat back levers  68   a,b  at each opposed seat position contribute to the positive retention of the seat back frame  69  during use in both sitting positions (FIG. 2). The two pair of levers  68   a,b  are interconnected to the seat back frame members by a link member  70 . The link member  70  is pivotally attached to the levers  68   a,b  by pins  72  and is affixed to the seat back frame  60 . The opposite vertical plates  12  at each side of the passenger seat  2  are integrally formed on an inwardly projecting pair of end locking block assemblies  80  (FIGS. 3 and 4) through which the end extensions  66   a ,  66   b  of the walkover tubes  62   a ,  62   b  extend for rotation.. The locking block assemblies  80  contain a lock member  82  and torsion dissipation section  84  of end extensions  66   a ,  66   b  which are described in my copending non-provisional application, Ser. No. ______, filed concurrently herewith.  
         [0017]    An inner plate  90  is affixed by threaded bolts and the like to the block assembly  80  and receive the end extensions  66   a ,  66   b  through aligned holes  91 . As seen in FIGS. 3 and 4, a seat cushion frame  92  possessing a pair of hollow support frame members  94  extends side to side of the passenger seat  2  in parallel relationship to the walkover tubes  62 . The frame members interconnect with end members  96  and an intermediate support member  98 .  
         [0018]    Movement of the seat back levers  68  and the end extensions  66  of the walkover tubes  62  is interconnected with the seat cushion frame  92  by heavy-duty cam assemblies  100  as seen in FIGS. 2 and 3, which are positioned on both sides of the seat  4 . The structure and function of the heavy-duty cam assemblies  100  on each side of the passenger seat  2  are identical. The cam assemblies  100  each include a pair of linkage members  102   a,b  having a curved outer concave cam surface  104 . It is within the scope of the invention to use other shapes for the cam surface  104 , if desired. The linkage members  102   a,b  are formed in a modified triangular shape having a hollow center area  106  surrounded by integral wall portions. The wall portions have a flat wall portion  108 , a generally flat wall section  110  having a depressed section  110   a , and a curved wall portion  112  which forms curved cam surface  104  on its outer face. An enlarged corner circular section  114  having a hole  114   a  is formed adjacent the junction of the curved wall portion  112  and the straight wall portion  108 . An enlarged comer circular section  115  is further formed at the junction between the straight wall portion  108  and the generally flat wall portion  110  and includes a hole  115   a . The curved wall portion  112  is integral to the generally flat wall portion  110  and includes a projecting end  116 , which forms a continuation of the cam surface  104 .  
         [0019]    The holes  114   a  of the linkage members  102   a,b  receive a pin  119  affixed to inner plate  90  to allow pivotal movement of the linkage members  102   a,b  relative to the inner plate  90 . Cam rollers  120  or other suitable cam followers are mounted on a respective lever  122  affixed to the end extensions  66   a ,  66   b , such that the roller  120  contacts the cam surface  104  of both linkage members  102   a,b  located on both sides of the car seat. In the first position shown in FIG. 2, the depressed section  110   a  of the generally flat wall  110  of linkage member  102   a  is facing upward to act as stop recess for a pin  124  affixed to the cushion frame member  92 , whereby the contacting surfaces of the pin  124  and the stop recess serve both as a support of the seat cushion frame  92  in the position shown and a stop to restrain motion upon movement of the seat back frame  60  between opposing positions. When the seat back frame  60  is moved to the opposed facing position than as shown in FIG. 2, the other link member  102   b  is rotated upward to expose its depression section  110   b  upward to receive a second stop pin  124  of the seat cushion frame  92  to restrain further movement of the linkage member  102   b  and support the seat cushion frame  92  as previously described, while the second linkage member  102   a  assumes a mirror image of FIG. 2. The heavy-duty cam assembly  100  does not require an additional latch and the like, but provides heavy duty structural support of the seat cushion frame  92  and the seat back frame  60  in absence of a main seat frame in accordance with the teachings of the invention.