Abstract:
A carrier assembly for a fifth wheel mounted on a semi-trailer tractor in which there are a pair of generally parallel spaced rail assemblies. Each of these rail assemblies comprises a bed plate, a rack of teeth superimposed over said bed plate and a rack cover plate superimposed over said rack of teeth and a plurality of vertical axially spaced bolting means extending through said rack cover plate, rack of teeth and base bed plate. The carrier assembly also includes a slider assembly comprising a pair of spaced generally parallel axial elements each of which is superimposed over one of said bed plates. There is also a transverse element connecting said generally parallel axial elements, and said slider assembly supports a tooth engaging means for selectively employed the rack of teeth on the rail assemblies. Arrangements are disclosed which enable the carrier assembly to be attached to the tractor and rear stops to be attached to the rest of the assembly without welding. Arrangements for facilitating motion of the slider assembly and for reducing or eliminating debris accumulation are also disclosed. Another arrangement is disclosed which resists shear forces. The present invention also encompasses a connecting and disconnecting device for a fifth wheel assembly.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]    This application is a divisional of nonprovisional application Ser. No. 09/613,329 filed Jul. 7, 2000, which claimed priority from provisional application Ser. No. 06/186,838 filed Mar. 3, 2000. This application incorporates by reference the disclosures of both of these applications. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    1. Technical Field  
           [0003]    This invention relates generally to fifth wheel assemblies for coupling semi-trailers to tractors. More particularly the invention relates to a method and apparatus for assisting the precise positionment of an adjustable fifth wheel carrier assembly.  
           [0004]    2. Background Information  
           [0005]    Large highway freight trailers are usually coupled to an associated tractor by means of a fifth wheel assembly whereby the tractor rear drive axles directly support a portion of the trailer load burden. Usually, the fifth wheel coupling and support point is located along the length of the tractor between the rear drive wheels and the front steering wheels thereby distributing the front trailer burden between the driver and the steering wheels. The exact percentage of load desirably placed upon the front steering wheels is a variable dependent upon many factors including the axle loading road surface, the tractor equipment, the weather, the weight of the trailer and the preference of the driver.  
           [0006]    Some degree of control over these variables is provided by a fifth wheel receiver that is mounted on a slide carrier assembly. The carriage assembly is rail guided and includes an anchoring mechanism for securing the slidable assembly at the desired point along the tractor length between the driving and steering wheel axles.  
           [0007]    In fifth wheel carrier assemblies heretofore in use, the parallel rail assemblies have been welded to an angle that is bolted to the frame of the tractor. This arrangement is inconvenient for original equipment manufacturer, (O.E.M.) installation and may result in welds which may be disuniform and possible damage to the tractor body when it becomes necessary to remove and replace the carrier assembly. Replacing the carrier assembly, which is fixed to the tractor in this way, also usually necessitates the use of a relatively centralized maintenance facility for this procedure. A need, therefore, exists for a way to assemble and mount the fifth wheel carrier assembly on a tractor at other locations and to do so without the detriments attended to welding.  
           [0008]    Heretofore, such fifth wheel carrier assemblies have also conventionally been provided with a stop feature that prevents rearward movement of the slider assembly. These stop features have usually been welded to the rail assembly.  
           [0009]    Many O.E.M. fifth wheel installations are ordered for dealer inventory and showrooms. When a purchaser is identified, it is often necessary (due to customer specifications) to change the fifth wheel height. Thereby, necessitating removal of this carriage assembly. A need, therefore, exists to provide easy removal of the rear stop to facilitate an easy change in fifth wheel height.  
           [0010]    A second disadvantage to such construction is that there may be quality concerns with the welds and cracks may develop after use in the field. A need exists, therefore, for a way to place such stop features which avoids these problems.  
           [0011]    Another problem which has sometimes been experienced with the prior art systems is that substantial resistance to moving the slider assembly on the rail assemblies may develop with the result that part wear may increase and substantially more force may be required to move the slider assembly. Accordingly, there is a need for a means to increase the ease of moving the slider assembly on the rail assemblies.  
           [0012]    It is also found that debris may tend to infiltrate and accumulate in the carrier assembly. Such debris may necessitate increased maintenance or may reduce the life of the assembly. A need, therefore, also exists for a way to reduce or eliminate such debris infiltration.  
           [0013]    When a semi-trailer/tractor starts and stops suddenly, large loads may be created on the fifth wheel carrier locking (plunger/rack interface) ably. It is desirable to distribute these loads over several mounting bolts, thus reducing the shear load. There is, therefore, a need for a way of providing support against such shear loads.  
           [0014]    The carriage locking device on prior art relies upon spring force to close and hold the locking plungers in. There is a need to provide a convenient way to close the locking mechanism, to identify that the lock in plungers are engaged and provide a secondary lock in device to ensure that they stay locked once closed. As the locking plungers and rack wear (through use) it is desirable to adjust for this wear.  
           [0015]    Finally, when connecting a trailer a locking mechanism is desirable that assures the driver that it is closed, is readily inspectable that is locked and provides a secondary security to keep it closed. In many commonly used arrangement, there is no such device, or if provided it often requires release the secondary security device to the use of two hands. A need, therefore, exists for a connection and disconnection mechanism which provides a secondary security device that can be easily inspected and can be operated quickly and easily using only one hand.  
         SUMMARY OF THE INVENTION  
         [0016]    It is an objective of the present invention to provide a way to fix fifth wheel carrier assemblies to the tractor and to form integrated rail elements without the necessity of welding.  
           [0017]    It Is another objective of the present invention to provide a rear stop for a fifth wheel carrier assembly without having to weld such features onto the carrier base so that the slider assembly can be easily removed from the rail assemblies.  
           [0018]    It is also an objective of the present invention to provide a means for more easily moving the slider assembly on the rail assembly elements of a fifth wheel carrier assembly.  
           [0019]    It is still another objective of the present invention to provide a way to reduce or eliminate the infiltration and accumulation of debris in the carrier assembly.  
           [0020]    It is also an objective of the present invention to provide a means for shear load sharing when a tractor moves from a linear path to a curve.  
           [0021]    It is also an objective of the present invention to provide a slide locking mechanism that contains a secondary securing mechanism that is reading inspectable for proper locking and ensures that it remains locked.  
           [0022]    It is still a further objective of the present invention to provide a means for quickly and easily operating the connection and disconnection mechanism on the fifth wheel assembly.  
           [0023]    In one embodiment of the present invention there is a carrier assembly for a fifth wheel mounted on a semi-trailer tractor in which there are a pair of generally parallel spaced rail assemblies. Preferably each of these rail assemblies comprises a bed plate, a rack of teeth superimposed over said bed plate and a rack cover plate superimposed over said rack of teeth and a plurality of vertical axially spaced bolting means extending through said rack cover plate, rack of teeth and base bed plate. The assembly also includes a slider assembly comprising a pair of spaced generally parallel axial elements each of which is superimposed over one of said bed plates. There is also a transverse element connecting said generally parallel axial elements and supporting a tooth engaging means for selectively employing the rack of teeth on the rail assemblies. The slider assembly may then be fixed in an axial position when said tooth engaging means are employed. Axial movement of the slider on said bed plates is also possible when the tooth engaging means are not employed to permit a positional adjustment of said fifth wheel on the trailer. In this embodiment the rail assembly is connected to the tractor by bolting means which preferably will also be used to form the bed plate, rack of teeth and rack cover plate into an integral rail assembly. The disadvantages of bolting the rail assemblies to the tractor are thereby avoided.  
           [0024]    Another embodiment of the invention comprises a carrier assembly in which there are a pair of generally parallel spaced rail assemblies extending from a front end of said carrier assembly to a rear end of said carrier assembly. The slider assembly comprises a pair of spaced generally parallel axial elements each of which is superimposed over one of said bed plates, and a transverse element connects said generally parallel axial elements and supports a tooth engaging means for selectively employing said rack of teeth to cause the slider to be fixed in an axial position when said tooth engaging means are employed. Axial movements of said slider on said bed plates is possible when said tooth engaging means are not employed to permit a positional adjustment of said fifth wheel on the trailer. A rear stop is bolted to the rail assemblies by means of this invention, the slider assembly can be easily removed from the rail assemblies.  
           [0025]    In another embodiment of the present invention, there is also a pair of generally parallel spaced rail assemblies on which a slider assembly, as is described above, is superimposed. To allow the slider assemblies to be moved more easily on the bed plates by increasing contact area, slidable plates which extend laterally beyond the lateral edges of the rail assemblies are interposed between the lateral elements of the slider assemblies and the bed plate.  
           [0026]    The present invention also includes an embodiment in which there is a pair of generally parallel spaced rail assemblies extending from a front end of said carrier assembly to a rear end of said carrier assembly. Each of said rail assemblies comprises a bed plate, a rack of teeth superimposed over said bed plate and a rack cover plate superimposed over said rack of teeth. There is also a slider assembly as described above which is superimposed over the rail assemblies. The rack cover plate extends over the rack of teeth and overlaps the bed plate. Infiltration and accumulation of debris is thus avoided by this arrangement.  
           [0027]    There is also another embodiment in which a pair of generally parallel spaced rail assemblies extending from a front end of said carrier assembly to a rear end of said carrier assembly. Each of said rail assemblies comprising a bed plate, a rack of teeth superimposed over said bed plate and a rack cover plate superimposed over said rack of teeth. The slider assembly comprises a pair of spaced generally parallel axial elements each of which is superimposed over one of said bed plates and a transverse element connecting said generally parallel axial elements and there is a tooth engaging means for selectively employing said rack of teeth on the rail assemblies to cause the slider to be fixed in an axial position when said tooth engaging means are employed and to allow axial movements of said slider on said bed plates when said tooth engaging means are not employed to permit a positional adjustment of said fifth wheel on the trailer. The rack of teeth is comprised of a plurality of generally uniform axially aligned teeth having spaces between adjacent teeth. The teeth on each of the parallel axially spaced rails are positioned in opposed relation to the teeth on the other of said axially spaced rails and at a position over at least one of the teeth the rack cover and the bed plate are pressed against said tooth, so as to share shear load resulting from sudden starts and stops so as to reduce shear loads at any one position.  
           [0028]    In another embodiment an improved means of operating the connecting and disconnecting mechanism is provided. This embodiment comprises a lever, from which a lock bar extends. A “C” shaped lock jaw is retained by the lock bar in a locked position, but is biased to move to an unlocked position when the lever is pivoted to move the lock bar so as to at least partially release the lock jaw from the lock bar and allow the lock jaw to move to an unlocked position. Preferably the lever is moved by a handle that extends laterally from one of its end outside the fifth wheel assembly. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0029]    The preferred embodiment of the invention, illustrative of the best mode in which applicant contemplated applying the principles, is set forth in the following description and is shown in the drawings and is particularly and distinctly pointed out and set forth in the appended claims.  
         [0030]    [0030]FIG. 1 is a side elevational view of a tractor trailer combination on which various aspects of the present invention are illustrated;  
         [0031]    [0031]FIGS. 2 a ,  2   b ,  2   c , and  2   d  are respectively a perspective, top plan, side and front view of a preferred embodiment of the carrier assembly for a fifth wheel of the present invention;  
         [0032]    [0032]FIG. 3 is a perspective exploded view of the carrier assembly shown in FIGS. 2 a - 2   d;    
         [0033]    [0033]FIG. 4 is a top plan schematic view of a pair of rail assemblies used in a prior art carrier assembly;  
         [0034]    [0034]FIG. 5 is an end view of a prior art rail assemblies shown in FIG. 4;  
         [0035]    [0035]FIG. 6 is a schematic end view of a pair of rail assemblies along with relating apparatus used in the carrier assembly of the present invention;  
         [0036]    [0036]FIG. 7 is a top plan view of a rack cover plate used in a rail assembly of the carrier assembly shown in FIGS. 2 a - 2   d;    
         [0037]    [0037]FIG. 8 is an end view of the rack cover plate shown in FIG. 7;  
         [0038]    [0038]FIG. 9 is a detailed view of the area in circle  9  in FIG. 8;  
         [0039]    [0039]FIG. 10 is a top plan view of the integral rack used in a rail assembly of the carrier assembly shown in FIGS. 2 a - 2   d;    
         [0040]    [0040]FIG. 11 is a front elevational view of the integral rack shown in FIG. 10;  
         [0041]    [0041]FIG. 12 is a top plan view of the bed plate used in a rail assembly of the carrier assembly shown in FIGS. 2 a - 2   d;    
         [0042]    [0042]FIG. 13 is a front view of the bed plate shown in FIG. 13;  
         [0043]    [0043]FIG. 14 is a detailed view of the area in circle  14  in FIG. 13;  
         [0044]    [0044]FIG. 15 is a top plan view of a rear stop used in the carrier assembly shown in FIGS. 2 a - 2   d;    
         [0045]    [0045]FIG. 16 is an end view of the rear stop shown in FIG. 15;  
         [0046]    [0046]FIG. 17 is a schematic top view of a rail assembly with welded rear stops used in a prior art carrier assembly;  
         [0047]    [0047]FIG. 18 is an end view of the rail assembly with welded rear stops shown in FIG. 17;  
         [0048]    [0048]FIG. 19 is a schematic top plan view of the rail assembly with rear stop used in the carrier assembly shown in FIGS. 2 a - 2   d;    
         [0049]    [0049]FIG. 20 is an end view of the rail assemblies and rear stop shown in FIG. 19;  
         [0050]    [0050]FIG. 21 is a fragmented side elevational view of a rail assembly used in the carrier assembly shown in FIG. 1;  
         [0051]    [0051]FIG. 22 is a schematic end view of a pair of rail assemblies showing slide features used in a prior art carrier assembly;  
         [0052]    [0052]FIG. 23 is a schematic end view of a pair of rail assemblies including a sled feature as may be used in a carrier assembly as shown in FIGS. 2 a - 2   d;    
         [0053]    [0053]FIG. 24 is a bottom plan view of a fifth wheel which includes a preferred opening feature of the present inventions in a locked position;  
         [0054]    [0054]FIG. 25 is an end view of the fifth wheel shown in FIG. 24;  
         [0055]    [0055]FIG. 26 is a cross sectional view through  26 - 26  in FIG. 24;  
         [0056]    [0056]FIG. 27 is a bottom plan view of the fifth wheel shown in FIG. 24 in an intermediate opening position;  
         [0057]    [0057]FIG. 28 is an end view of the fifth wheel shown in FIG. 27;  
         [0058]    [0058]FIG. 29 is a bottom plan view of the fifth wheel shown in FIG. 25 in an open position; and  
         [0059]    [0059]FIG. 30 is an end view of the fifth wheel shown in FIG. 29. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0060]    Referring to FIG. 1, a highway tractor-trailer unit  10  is shown to include a powered tractor  12  and a trailer  14  connected by a fifth wheel hitch assembly  16  for relative articulation about a vertical axis. As is explained in greater detail hereafter, the fifth wheel is mounted on a carrier assembly  18 . Propulsive power of the tractor unit  12  is delivered to driving wheels  20 . Tractor directional steering is controlled by front wheels  22 . Trailer secured wheels  24  carry the aft end of the trailer load and are served by a braking mechanism that may be engaged independently of the tractor wheel brakes.  
         [0061]    To illustrate the objective of a position adjustable fifth wheel unit  16  the value X is shown as the distance between the fifth wheel vertical hitch axis  26  and the tractor steered wheel plane  28 . If the fifth wheel hitch axis  26  is shifted to the aft of the tractor by a distance Y the percentage of trailer load carried by the tractor steering wheels is correspondingly reduced and the load carried by the tractor driving wheels  20  is increased.  
         [0062]    Referring to the figures generally and in particular to FIGS. 2 a - 2   d  and  3 , the carrier assembly is shown generally at numeral  30 . This carrier assembly  30  has a base made up of spaced parallel rail assemblies  32  and  34 . Each of these rail assemblies includes a bed plate  36  an integral rack of teeth  38  and a rack cover plate  40 . On the bed plate there are a plurality of bolt receiving apertures as at aperture  42  (FIG. 12). On the integral rack of teeth  38  there are a plurality of apertures as at aperture  44  which are aligned with apertures on the bed plate  36 . On the rack cover plate  40  there are also a plurality of bolt receiving apertures as at aperture  46  and each of these apertures are aligned with apertures in the bed plate  36  and the integral rack of teeth  38 . These aligned apertures receive bolts as at bolt  48  which are engaged with a nut  50  (FIGS. 2 d  and  6 ). These bolt and nut combinations allow the rail assemblies  32  and  34  to be formed as an integral unit and also attach them to the frame  52  (FIGS. 2 d  and  6 ) of the tractor and thereby avoid welding. The rail assemblies as at rail assembly  32  also include shear resistance spacers  54  and  56  and bracket  58  which are connected to the assembly  30  respectively by bolts  128 ,  62  and  64 . These bolts are also connected by nuts as at nut  66  in the case of bolt  64 . As will be explained in greater detail hereafter, there are also extrusion apertures as at aperture  68  on the bed plate  36  and extrusion apertures as at aperture  70  on the rack cover plate  40 .  
         [0063]    Referring to the drawings generally and particularly to FIGS.  10 - 11 , it will be seen that the integral rack has a plurality of teeth as at tooth  72  mounted on a plate  74 . Between the teeth there are intermediate spaces as at space  76 . It will be understood that the plate  74  is integral with the teeth and may be either below or above them.  
         [0064]    Referring again to the drawings generally and in particular to FIGS. 2 a - 3 , the slider assembly is shown generally at numeral  78 . Included in the slider assembly  78  there is a pair of generally parallel axial members  80  and  82 . On each of these axial members there are respectively mounting brackets  84  and  86  for mounting the fifth wheel which is shown in FIG. 2 in phantom lines at numeral  87 . The mounting brackets  84  and  86  may preferably be welded directly to the parallel axial members  80  and  82  respectively. The slider assembly  78  has medial transverse members  88  and  90 . On transverse member  88  there is mounted lateral arm  92  which has distal fingers as at finger  94 . In opposed relation to lateral arm  92  there is a lateral arm  96  having distal fingers as at finger  98 . Restraining lateral arms  92  and  96  respectively there are springs  100  and  102 . Motion of these lateral arms is controlled in part by guide features as at features  104 ,  106 ,  108 , 110 , and  112 . There is also a pivot plate  113  and a mounting bar  114 , and lateral arm  92  is pivotally mounted on this pivot plate at pivot point  116  while lateral arm  96  is mounted at pivot point  118 . On the pivot plate  113  there is also a forward pivot point  120  at which it is connected to a spring biased piston and cylinder combination  122 . This piston and cylinder combination  122  is connected at its opposed end to member  80  of the slider assembly through member  125  (FIG. 3). Preferably, the piston and cylinder combination  122  is a pneumatic piston and cylinder combination. This piston and cylinder combination  122  is spring locked biased and centers the arm control plate  113  onto guide feature  106  which serves as a stop. The connection of the fingers as at  94  and  98  with each rack of teeth  38  respectively can be ascertained by visual inspection. It will be appreciated that a positive engagement is provided which does not rely solely on spring force. An automatic spring biased arrangement is thus provided for locking the carrier assembly, which compensates for tooth wear and construction inconsistencies. It will also be appreciated that this arrangement is a positive mechanical spring biased mechanism that securely maintains the carrier assembly in a locking position when it is engaged. On the rail assemblies there is also a front transverse member  126  which is connected to the bed plates  36  by welding. Bolts  128  and  130  also serve to hold the cover plates as at plate  40  to the rest of the rail assemblies  32  and  34  respectively. The rail assemblies also includes a rear stop member  132  from which brackets  58  and  133  extend which are connected to the rail assemblies by means of bolts  64  and  134  on bracket  58  and bolts  135  and  136  on bracket  133 .  
         [0065]    Differences between the carrier assembly and of the present invention and that of the prior art is explained with reference to FIGS.  4 - 5  and  17 - 18  and FIG. 22. Referring particularly to FIGS.  4 - 5 , the prior art method of welding the rail assemblies is explained in greater detail as follows. Such an arrangement would include a bed plate  138 , which has lateral mounting angles  140  and  142 . This bed plate  138  would be welded to the mounting angles  140  and  142  by means of weld points  144  and  146 . Parallel racks of teeth  148  and  150  would be welded onto the bed plate  138  by welds  152  and  154  respectively. A slide element  156  on the slider assembly is moved on the bed plate on brackets  158  and  160 . Similarly a lateral slider element  162  on the slider assembly is moved on the bed plate  138  on brackets  164  and  166 . Comparing this prior art arrangement with the apparatus of the present invention shown in FIG. 6, it will be appreciated that certain advantages are available with the apparatus of the present invention. First, in this prior art apparatus, welding the carrier assembly to the mounting angles is necessary. In the carrier assembly of the present invention, on the other hand, the rail assemblies  32  and  34  may be fixed to the tractor frame  52  by means of bolts and nut combinations as, for example, bolt  48  and nut  50 . Another advantage of the present invention is also apparent from a comparison of FIGS. 4 and 5 with FIG. 6. It will be appreciated that in FIG.  6  the rack cover plate  40  extends inwardly over the rack of teeth  38  to overlap the bed plate  36 . This overlap by the rack cover plate  40  reduces or eliminates the infiltration and accumulation of debris in the track assembly  32 .  
         [0066]    Referring to FIGS.  17 - 18 , a common prior art arrangement for providing rear stops for the slider assembly is shown. In this arrangement there is a bed plate  168  with opposed lateral slide curls  169  and  170 . To stop the slider assembly there are rear stops  171  and  172 . These rear stops are attached respectively to the bed plate  168  by welds  173  and  174 . The rear stops  171  and  172  are also attached to the mounting angles  169  and  170  by welds  175  and  176  respectively. It would be understood in the above described prior art arrangement, it would generally be necessary to cut the welded rear stops  171  and  172  in order to remove the slider assembly from the rail assemblies. On the other hand, in the arrangement of the present invention, the transverse rear stop  132  may be easily removed without damaging the rest of the assembly by loosening its attaching bolts so as to allow the slider assembly to be removed from the rail assemblies.  
         [0067]    Referring to FIG. 22, a common prior art arrangement for mounting the lateral slide elements on the bed plate is shown. In this arrangement there is a bed plate  178  over which a lateral slide element  180  is superimposed. Interposed between lateral slide element  180  and the bed plate there are brackets  182  and  184  which extend first downwardly then laterally from the lateral slide element. Similarly there is an opposed lateral slide element  186  from which brackets  188  and  190  extend to rest upon the bed plate in the same way. A comparative detailed view of the preferred embodiment of the present invention is shown in FIG. 23 in which there is a bed plate  192  over which the lateral element  194  rests on a sled  196 . This sled or slidable plate  196  has a flat base surface  198  which rests directly on the bed plate and an outward curved lateral surface  200 . There are also vertical support members  202  and  204  between the lateral element  194  and the flat base surface  198 . On the opposed side of the bed plate  192  there is another lateral element  205  which is superimposed on the sled or slidable plate  206  which also has a flat base surface  207  which rests on the other bed plate  208  which is in opposed relation to bed plate  192 . There is also a curved lateral surface  209  which curves upwardly and outwardly from the bed plate. Similarly there are vertical members  210  and  212  interposed between the lateral element  205  and the flat base surface  207 . It will be appreciated that in the above described embodiment of the present invention that the sleds or slidable plates  196  and  206  extend laterally beyond the sides of lateral elements  194  and  205 , respectively. It will also be appreciated that surface area between sleds or slidable plates  196  and  210  and the bed plate  192  is significantly increased over prior art arrangements (as for example brackets  182 ,  184 ,  188 , and  190 ) so as to allow the slider assembly to move with considerably greater ease and with less part wear.  
         [0068]    Referring to the drawings generally and in particular to FIG. 21, another embodiment of the present invention is shown. This drawing shows a fragmented section of rail assembly  32  in which the bed plate  36 , integral rack of teeth  38  and rack cover plate  40  are shown. Bolts  48  and  60  extend through the rack assembly as is described above and are secured respectively by nuts  50  and  212 . Also shown are tooth  72 , space  76  and tooth  213 . Elongated aperture  70  is in the rack cover plate  40  above tooth  213 , and elongated aperture  68  is in the bed plate below tooth  213 . Aperture  214  extends into tooth  213  and joins with the aforesaid apertures  68  and  70 . On the opposite side of tooth  213  from space  76  there is another space  215 . To provide additional resistance from shear forces when a semi trailer/tractor starts and stops suddenly, rack cover plate  40  is manipulated in the vicinity of aperture  70  to press the rack cover plate against tooth  213  as at bend  216 . Force is also applied to the bed plate  36  in the vicinity of aperture  68  to press the bed plate  36  against the tooth  213  as at bend  217 . Referring also to FIGS.  7 - 13 , it will be seen that there are a plurality of elongated apertures in the bed plate  36 , rack of teeth  38  and rack cover plate  40 . At each of these elongated apertures, the bed plate  36  and rack cover plate would be bent against an adjacent tooth in the way described above as at bends  218  and  219  respectively on FIG. 21.  
         [0069]    Referring to FIGS.  24 - 30 , an embodiment which is a locking mechanism for a fifth wheel assembly is shown. This fifth wheel assembly is shown generally at  220  and, except for the connecting and disconnecting mechanism described herein, is otherwise essentially conventional as is, for example, essentially disclosed in U.S. Pat. No. 5,746,438 to Bergmann et al. which is assigned to the assignee of this application and which is incorporated herein by reference. The assembly  220  includes a housing  222  with axial attachment points  226  and  228  for a carrier assembly. The assembly  220  also includes, as is conventional, rearwardly projecting ramps  230  and  231 , a kingpin receiving gap  232  and a blind port  234 . The locking and unlocking mechanism includes a lever  236  with a medial lever pivot point  238  and a front end  240  and a rear end  242  adjacent the medial lever pivot point  238 . There is a lock bar  244  which has a horizontal front edge  246  and a side oblique edge  248 . There is also a “C” shaped lock jaw  250  which has a pivot point  252 . The lock jaw has a first end  254  on a recessed leg  256  and a second end  258  on a major leg  260 . A biasing spring  262  is attached to the lock jaw  250  rearwardly from the pivot point  252 . At the front end  240  of the lever it is attached to a handle  264  at pivot point  266 . The handle  264  has an inner end  268  and an outer grip end  270  which is a loop configuration. The outer grip end  270  loop is obliquely configured to facilitate unlocking of the locking mechanism as is explained below. It will also be appreciated that this arrangement allows the user to easily and efficiently ascertain if the assembly  220  is properly locked by visually inspecting the handle  264 . At the inner end  268  the handle  264  is attached to biasing spring  272  which resists the withdrawal of the handle  264 . The handle  264  also has steps  274 ,  276  and  278  the function of which will be explained hereafter. There is also a leaf spring  280  which biases the handle  264  into a locked position. The handle  264  extends from the housing  222  through a handle aperture  282  which has a widened unlocked section  284  and a narrowed locked section  286 . The pivoting of the lever  236  at the handle end  268  forces spring  272  to bias handle  268  into the narrowed locked section  286 . The operation of the above described locking and unlocking mechanism is as follows. The locked position of the mechanism is shown in FIGS.  24 - 26 . In this locked position the lever  236  is in an oblique position with the handle  264  in an inward position. The lock jaw  250  is in a locked position with the horizontal front edge  246  of the lock bar  244  bearing against the recessed leg  256  of the lock jaw  250 . Referring particularly to FIG. 26, it will be seen that the leaf spring  280  bears against the handle  264  to maintain the handle  264  in a lower locked position. Referring particularly to FIG. 25, it will be seen that the handle  264  is in the lower locked position when in narrowed locked section  286  of the handle aperture  282 .  
         [0070]    Referring to FIGS.  27 - 28 , an intermediate stage in unlocking the fifth wheel assembly  220  is shown. The handle outer grip end  270  loop is orientated upon the handle  264  such that the effort of the driver pulling the handle loop will have a touch key to bias the handle  264  up against leaf spring  280  forcing the handle  264  into the widened unlocked section  284 . This orientation of the handle loop also biases the handle  264  forward allowing step  274  to pass through widened unlocked section  284 . Here force is applied against the leaf spring  280  to move the handle  264  upwardly to the widened unlocked section  284 , which is in an upper position of the handle aperture  282 . It will be appreciated that in this upper position it is possible for the step  274  to move through the handle aperture  282  while in the lower narrowed locked section  286  the same would not be possible.  
         [0071]    It will be appreciated that this arrangement provides a readily apparent visual indication of whether the assembly  220  is locked or not. That is, the handle  264  will be positioned in section  284  in an unlocked position and in section  286  in the locked position.  
         [0072]    Referring to FIGS.  29 - 30 , the final step in unlocking the fifth wheel assembly  220  is illustrated. Here the handle  264  is pulled outwardly beyond step  276 , pivoted forward and released so that step  276  is engaged on the housing  222 . This action is performed against biasing spring  272 . As the driver pulls the tractor forward, the motion of the lockjaw  250  causes leg  260  to drive lever  236  outward releasing handle  264  from step  276  on housing  222  thereby setting the locking mechanism for recoupling. It will be appreciated that this method of unlocking the fifth wheel assembly  220  is quick and efficient and will usually be able to be accomplished with one hand.  
         [0073]    It will be appreciated that whether the assembly  220  is locked or unlocked is also readily apparent from the position of the handle  264 . That is, when the step  276  engages the housing  222 , the assembly  220  will be unlocked.  
         [0074]    It will be appreciated that there has been described a carrier assembly in which the disadvantages of welding the assembly to the tractor are avoided. This carrier assembly also allows the rear stops to be easily and economically removed to facilitate removal of the slider assembly. This carrier assembly also includes features which facilitate movement of the slider assembly on the rail assembly and reduce part wear. This carrier assembly also reduces or eliminates debris infiltration into the apparatus and which shares shear loads. It will also be appreciated that means have been described which allow quick and easy connection and disconnection of the fifth wheel and which provides means for quick visual to ascertain whether the assembly in locked or unlocked.  
         [0075]    Accordingly, the improved Carrier Assembly for a Fifth Wheel apparatus is simplified, provides an effective, safe, inexpensive, and efficient device which achieves all the enumerated objectives, provides for eliminating difficulties encountered with prior devices, and solves problems and obtains new results in the art.  
         [0076]    In the foregoing description, certain terms have been used for brevity, clearness, and understanding; but no unnecessary limitations are to be implied therefrom beyond the requirement of the prior art, because such terms are used for descriptive purposes and are intended to be broadly construed.  
         [0077]    Moreover, the description and illustration of the invention is by way of example, and the scope of the invention is not limited to the exact details shown or described.  
         [0078]    Having now described the features, discoveries, and principles of the invention, the manner in which the Carrier Assembly for a Fifth Wheel is constructed and used, the characteristics of the construction, and the advantageous new and useful results obtained; the new and useful structures, devices, elements, arrangements, parts, and combinations are set forth in the appended claims.