Abstract:
A bellows for an articulating vehicle has improved performance by using fewer discrete pieces of flexible material, and a multi-piece frame. By using fewer pieces of flexible material, less stitching is required, which results in improved performance and ease of manufacture.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application is based on and claims priority to U.S. Provisional Patent Application No. 61/862,887 filed on Aug. 6, 2013, which is incorporated herein by reference in its entirety for all purposes. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates generally to the field of protective coverings which extend and retract. More particularly, the present invention relates to a bellows which can be used on an articulating vehicle such as, but not limited to, an articulating bus. 
       BACKGROUND 
       [0003]    Large bellows that are used to protect a moveable connection such as on an articulating vehicle typically have a pleated type construction manufactured from many pieces of coated fabric that are sewn together and supported by perimeter frames. In some constructions the perimeter frames may be located at the outer perimeter of the fabric pleats. In other constructions, the perimeter frames may be located along the inner perimeter of the fabric pleats. In constructions where the frames are located at the outer perimeter, the fabric pleats are typically made of separate fabric pieces that are stitched together to form the folds of the pleat, resulting in a “V” shaped cross-section, referred to as a folding construction. In another construction having the frames located at the outer perimeter, the fabric is allowed to remain as a flat piece, which results in a “U” shaped cross-section. This alternate method of construction is often referred to as a corrugated construction. Due to the “U” shape of these bellows, separate fabric pieces are used to create the pleated shape. Like the previously described construction, the fabric pieces are joined together on the edges by the perimeter frames or by stitching. 
         [0004]    Assembly of typical articulating vehicle bellows is a labor intensive process that requires the handling of numerous individual fabric panels, alignment of inner and outer edges of each of the fabric panels, and then stitching the panels together or crimping the aluminum support frames to the fabric panels to create the final configuration. As shown in  FIGS. 1-3 , typical folding type bus bellows  10  require fourteen individual panels per section, with ten sections, or  140  individual panels per assembled bellows. Typical corrugated bellows will require seventeen individual panels per section, with ten sections, or  170  individual panels per assembled bellows. 
         [0005]    Additionally, as shown in  FIG. 3 , perimeter frames  20  used in typical articulating vehicle bellows  10  must be very large because they are formed to the entire perimeter shape. Such large perimeter frames  20  require that the bellows  10  be assembled one folding, or corrugated section, at a time with each section having a perimeter frame  20  and a fabric section  22  made from the many individual panels. 
         [0006]    An additional drawback to traditional articulating vehicle bellows is that a significant amount of stitching is required to join the individual fabric pieces together as well as to join the assembled fabric pieces to one another in creating individual folding sections. A typical bellows having the multitude of fabric panels described above requires over 2,500 inches of stitching to create the folding sections. Every inch of the stitching also requires manual sealing in order to prevent liquid or air from penetrating the seams. The sealing of the seams is commonly accomplished by using an adhesive or caulk type sealer, and is typically a manual process. 
         [0007]    As shown in  FIGS. 1B and 1C , typical folding bellows  10  also require that the corner fabric pieces  24 ,  26  be individual panels with rounded shaped corners to transition from a horizontal side to a vertical side. The individual corner fabric pieces  24 ,  26  which are used to create the radius corner result in a large amount of material scrap due to their shape and inability to be nested closely in a CNC fabric cutting program. Additionally, the radius corners are subject to a large amount of stress because they must be tight enough to provide support to the bellows  10  in the standard mounted position and to prevent excessive sagging of the bellows, but also allow the folds to open enough so that the bellows can make a large extension when an articulating vehicle turns. This requires the corner pieces and corner stitching to be stretched tightly during the turn. 
         [0008]    There have been efforts to use a folding corner in some cases to replace the rounded corners of the bus bellows. In one case, a tongue-in-groove type folding arrangement is used to transition the pleats from a horizontal side to a vertical side. This folding arrangement has drawbacks due to the significant flexing stress placed on the fabric material which leads to premature flex fatigue failure of the fabric which results in a hole in the fabric, and thus, an inability of the bellows to prevent air and liquid from intrusion into the area to be protected. 
         [0009]    Another common folding arrangement has a chamfered or mitered corner. This folding arrangement allows the fabric material to roll, rather than crease which results in less flex fatigue placed on the fabric. Both of the folding arrangements previously described have been common to the manufacture of standard folding bellows for a very long time. Both folding arrangements can also allow for a larger opening of a corner than the rounded shaped corner allows for and thus make it possible to reduce the number of folds. 
         [0010]    Accordingly, there is a need for a bellows design that allows for a less complex and expensive method of manufacture by using fewer fabric panels, less material, and requiring less, and easier, handling of the fabric and support frames. There is also a need for a bellows that does not require manual sealing of the stitching holes that are created in a typical folding type articulating vehicle bellows. 
       SUMMARY 
       [0011]    The present invention is a bellows for an articulating vehicle having an assembled flexible material layout including a left bottom corner flexible portion, a left side flexible portion, a left top corner flexible portion, a top flexible portion, a right top corner flexible portion, a right side flexible portion, and a right bottom corner flexible portion. One end of the left bottom corner flexible portion is attached to a first end of the left side flexible portion, and a second end of the left side flexible portion is attached to a first end of the left top corner flexible portion. A second end of the left top corner flexible portion is attached to a first end of the top flexible portion, and a second end of the top flexible portion is attached to a first end of the right top corner flexible portion. A second end of the right top corner portion is attached to a first end of the right side flexible portion, and a second end of the right side flexible portion is attached to a first end of the right bottom corner flexible portion. 
         [0012]    A plurality of external side support frames are attached to the right and left side flexible portions, and a plurality of internal side support frames are attached to the right and left side flexible portions. Each of the internal side support frames has a top and bottom connecting plate for connecting the internal side support frames to the external support frames. A plurality of top support frames are attached to the top flexible portion and further attached to the top connecting plates, and a plurality of bottom support frames are attached to the left bottom corner and right bottom corner flexible portions and further attached to the bottom connecting plates. 
         [0013]    It will be understood by those skilled in the art that one or more aspects of this invention can meet certain objectives, while one or more other aspects can lead to certain other objectives. Other objects, features, benefits and advantages of the present invention will be apparent in this summary and descriptions of the disclosed embodiment, and will be readily apparent to those skilled in the art. Such objects, features, benefits and advantages will be apparent from the above as taken in conjunction with the accompanying figures and all reasonable inferences to be drawn therefrom. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]      FIG. 1A  is a schematic view of the material requirements for the top section of a typical prior art folding type bus bellows; 
           [0015]      FIG. 1B  is a schematic view of the material requirements for the top radius corners of a typical prior art folding type bus bellows; 
           [0016]      FIG. 1C  is a schematic view of the material requirements for the bottom radius corners of a typical prior art folding type bus bellows; 
           [0017]      FIG. 1D  is a schematic view of the material requirements for the side sections of a typical prior art folding type bus bellows; 
           [0018]      FIG. 2  is a schematic view of an assembled folding section for a typical prior art folding type bus bellows; 
           [0019]      FIG. 3  is a schematic view of a support frame arrangement for a typical prior art folding type bus bellows; 
           [0020]      FIG. 4  is a perspective view of one embodiment of a bellows in accordance with the invention; 
           [0021]      FIG. 5  is an exploded schematic view of the bellows in of  FIG. 4 , showing each of the flexible panels; 
           [0022]      FIG. 6  is a schematic view of one embodiment of a slit and tab arrangement of a flexible piece in accordance with the invention; 
           [0023]      FIG. 7  is a schematic view of the bellows of  FIG. 4 , showing the flexible panels assembled together; 
           [0024]      FIG. 8  is a schematic view of the bellows of  FIG. 4  showing the flexible material pleated with internal side frames, external side frames, and external lower frames mounted in a pleated strip configuration; 
           [0025]      FIG. 8A  is a section view of the bellows of  FIG. 7  taken generally along the line  8 A- 8 A in  FIG. 8 ; 
           [0026]      FIG. 9  is a front view of the bellows of  FIG. 4  showing outer top frames joining the internal side frames together to form the bellows shape; 
           [0027]      FIG. 10  is a detail perspective view of the bellows of  FIG. 4  showing the pleated flexible pieces prior to mounting support frames; 
           [0028]      FIG. 11  is a detail perspective view of the bellows of  FIG. 4  showing the side and lower folding parts of the flexible material with internal and external support frames; 
           [0029]      FIG. 12  is a detail perspective view of the bellows of  FIG. 4  showing the side and lower portion of the bellows with connecting frames fastened in place and opened to show the folding corner; 
           [0030]      FIG. 13  is a detail perspective view of the bellows of  FIG. 4  showing the external side support frames as well as the upper and lower folding corners; 
           [0031]      FIG. 14  is a detail perspective view of the bellows of  FIG. 4  showing the external side support frames, the upper folding corner, and the top support frames; 
           [0032]      FIG. 15  is a detail perspective view of the bellows of  FIG. 4  showing the lower support frames; 
           [0033]      FIG. 16  is a detail perspective view of the bellows of  FIG. 4  showing the internal side support frame; 
           [0034]      FIG. 17  is a detail perspective view of the bellows of  FIG. 4  showing an internal side support frame and an upper connecting plate to which the external top support frame is attached; and 
           [0035]      FIG. 18  is a detail schematic view the bellows of  FIG. 4  showing an internal side support frame, connecting plates, and lower connecting channel forming a continuous hoop when assembled. 
       
    
    
     DETAILED DESCRIPTION 
       [0036]    A bellows  12  for an articulating vehicle in accordance with the invention has a reduced number of flexible pieces and support frames. In the embodiment shown in  FIGS. 4-18 , only seven flexible pieces  100  are required to form the entire bellows, compared to over one hundred pieces for a conventional articulating vehicle bellows described previously. Referring to  FIG. 5 , the flexible pieces  100  are left bottom corner  102 , left side section  104 , left top corner  106 , top portion  108 , right top corner  110 , right side section  112 , and right bottom corner  114 . The flexible pieces  100  are typically made of a fabric substrate based material that has a coating of elastomer or thermoplastic. It is also possible to use a plastic sheet in some parts of the bellows  12  which are not subject to folding stresses, the sides for example. Of course, any other suitable material may alternatively be used for the flexible pieces  100  without departing from the invention. Additionally, the flexible pieces  100  need not all be made of the same material. The flexible pieces  100  are configured such that each can be a single piece, two pieces, or any other number as necessitated by the bulk size of the flexible material. The flexible pieces  100  are then cut with a series of slits and connecting tabs, as well as other necessary cutouts which, when folded, will produce the desired shape of the assembled bellows. The shapes and sizes of the slits, connecting tabs, and cutouts can be any shape and size depending on the desired size and shape of the finished bellows  12 . A CNC programmed cutting machine may be used to cut the flexible pieces  100 , but the patterns could also be hand marked and hand cut to achieve the same result.  FIG. 5  shows a detailed view of the left top corner  106 , which includes a plurality of slits  116  and connecting tabs  118  that combine to form the folds of the completed bellows  12 . 
         [0037]    In the embodiment shown, there are no slits to define the top folds. Rather, the flexible material is allowed to take on a rolled shape as in a corrugated bellows. This method of construction serves two purposes. First, there is no need for an inside top support frame and as such it would be desirable to not have any valley type seam as in a conventional bellows. The second purpose is to allow for ease of movement when the articulation area is extended as when a vehicle travels through a turn. 
         [0038]    As shown in  FIG. 7 , once the required flexible pieces  100  have been cut to size and shape, they are assembled into an assembled flexible material layout  122  using overlapping type seams  120 . In the embodiment shown, only six seams are needed to form the assembled flexible material layout  122  for the bellows  12 . These seams  120  can be stitched, bonded, taped, or sealed to provide the proper connection required for the use of the bellows  12  on a transit bus, rail vehicle, or similar duty use. The resultant assembled flexible material layout  122  will be a large pattern with the slits  116 , tabs  118  and cutouts located such that when folded into a pleated configuration and then formed into a circumferential shape, the assembled flexible material layout  122  will locate itself into the required dimensional locations. The slits  116  and tabs  118  that are cut into the flexible pieces  100  allow the assembled flexible material layout  122  to be folded in an accordion manner with alternating fold directions. 
         [0039]      FIGS. 8-9  show the bellows  12  in a folded configuration with support frames  200  attached. As shown, there are side internal support frames  202  and side external support frames  204  that replace the stitching of traditional articulating vehicle bellows with a seamless, gutter shaped channel. Additionally, the support frames  202 ,  204  provide barriers that prevent liquid or gas penetration into or out of the bellows  12 . It may also be desirable to use an adhesive, tape, or alternate material joining method prior to folding the fabric in an accordion manner to provide an additional barrier and also help maintain the folded accordion shape. Alternatively, staples or similar fastening methods may be used to hold the folded shape. In the embodiment shown, the support frames  202 ,  204  are made of aluminum, but any suitable material may be used without departing from the invention. 
         [0040]    As shown in  FIG. 9 , the support frames  202 ,  204  are smaller and use less material than typical articulating vehicle bellows support frames (see  FIG. 3 ). A plurality of side internal support frames  202  are used on each inside side surface of the bellows  12 , a plurality of side external support frames  204  are used on an external side surface of the bellows, top external support frames  206  at the top of the bellows  12 , and lower external frames  208  at the bottom of the bellows. Connecting plates  210  are mounted at each end of the side external support frames  202 . The connecting plates  210  allow the top external support frames  206  and the lower external support frames  208  to be mechanically connected to the side internal frames  202 . In the embodiment shown, the support frames  206 ,  208  are riveted to the connecting plates  210 , but any suitable attachment may be used without departing from the invention. 
         [0041]    The chamfered corner arrangement shown in  FIGS. 10-12 , in which an outer fold on one side transitions to an inner fold on an adjacent side, and vice versa, allows for this to occur. Alternatively, the side external support frames  204  may be installed with a slight offset and the connecting plates  210  configured such that they attach to the offset and allow the side internal support frame  202  to connect to the top external support frame  206 . Such a configuration negates the need to bend a radial arc into the support frame. As shown in  FIG. 18 , a lower connecting channel  212  will then mount to the lower external support frames  208  so that when completely assembled, a fully connected, solid support frame exists for each fold. 
         [0042]      FIGS. 13-18  are various detail views of a fully assembled bellows  12 .  FIG. 13  shows a fully assembled bellows  12 , with the folds partially extended, showing the seamless folds formed between the side external support frames  204  and between the top and bottom external support frames  206 ,  208 .  FIG. 14  is a detail view showing the upper corner folds achieved in the present embodiment.  FIG. 15  is a detail view showing the lower corner folds of the present embodiment.  FIG. 16  shows the interior structure of the bellows  12  with the folds partially extended so that the side internal support frames  202  are visible.  FIG. 17  is a detail view showing the connector plate  210  attached to the side internal support frame  202 . 
         [0043]    Although one embodiment is described in detail herein, alternative configurations of the support frame can that serve the same purpose do not depart from the invention. For example, a single lower external support frame can replace the two short lower external support frames  208  and connecting channel  212  to produce the same connected solid frame. Another example is that the connecting plates  210  can be assembled to the upper external support frames  206  rather than the side internal support frames  202 . This embodiment would allow the straight pleated shape to be transported in a manageable configuration with all of the necessary frames attached and then simply formed and connected with internal fasteners for final assembly. 
         [0044]    The movement of an articulated bus is a combination of an opening fan motion and a shearing motion. In a standard bellows configuration, the shearing motion results in a force that is great enough to form an S shape into the support frames. By creating a rolled shape with the flexible material, the shearing motion is taken up by the flexible material rather than the rigid support frames. 
         [0045]    The assembly of the bellows  12  involves crimping, or staking, the support frames to the folded peaks of the flexible material  100  as defined by the slits  116  and cutouts in the flexible material after it has been folded into a pleated shape. In the embodiment described herein, the internal and external side support frames  202 ,  204  are connected to the fabric peaks first. Next, the lower fabric is folded and connected to the support frames by crimping the frame to the fabric and mechanically connecting the lower external support frame  208  to the connecting plate  210  by riveting, for example. Next, the upper corners are formed by crimping the top external support frame  206  onto the fabric, and connecting the top external support frame to the connecting plate  210 . This process will be repeated for each folding section that is required. The last fold can be adapted to many different configurations as required by the end user. 
         [0046]    Although the invention has been herein described in what is perceived to be the most practical and preferred embodiments, it is to be understood that the invention is not intended to be limited to the specific embodiments set forth above. Rather, it is recognized that modifications may be made by one of skill in the art of the invention without departing from the spirit or intent of the invention and, therefore, the invention is to be taken as including all reasonable equivalents to the subject matter of the appended claims and the description of the invention herein.