Abstract:
A removable gooseneck hitch assembly transitions between an afterward position for hitching to a low bed trailer deck and a forward position by a pivoting arm that moves the forward end of the gooseneck an arcuate path. The invention minimizes the opportunity for debris to interfere with the sliding track assemblies known in the prior art. The assembly provides three degrees of freedom for the gooseneck in low bed mode and restricts the degrees of freedom in vehicle towing mode. A locking member for securing a low bed trailer hitch is also disclosed.

Description:
FIELD OF THE INVENTION 
       [0001]    This invention relates to hydraulic gooseneck hitches for heavy haul trailers. In particular, this invention relates to an articulation mechanism for a gooseneck arm, to means for hitching the gooseneck and hitch assembly to a low bed trailer deck or to a towed vehicle, to means for transitioning between the low bed mode and the towed vehicle mode, and to means for locking the gooseneck and hitch assembly to a low bed trailer deck. 
       BACKGROUND OF THE INVENTION 
       [0002]    Sliding fifth wheel and gooseneck assemblies have been a common feature of heavy haul low bed semi trailers for several decades. They are found on every type of truck and trailer combination from on-road 30 ton single axle jeeps to off-road 200 ton mine trailers. The sliding assemblies are used to move the down or bearing point of the semi-trailer forward or backward to change the weight distribution on the tractor vehicle, in some cases to accommodate a transition from towing a low bed deck to towing an incapacitated vehicle. Such an assembly must also be capable of lowering the hitch assembly to allow it to be attached to a low bed deck, and of raising it to provide ground clearance when the deck is unhitched. 
         [0003]    Examples of sliding fifth wheel and gooseneck assemblies are provided in Canadian Patent No. 2,080,446 and in the trailers manufactured by Kalyn Siebert, Peerless Limited, Scona Trailer Manufacturing, XL Specialized Trailers Inc., Cozad Trailers Sales LLC, Trail King Industries and Murray Trailer. 
         [0004]    While several variations of sliding fifth wheel and gooseneck assemblies exist, they are all subject to a significant limitation—they can get stuck. Heavy-haul low bed trailers work in sometimes very harsh environments such as mines and they spend the majority of their life unprotected from the elements and from local debris. As a result, it is common for the sliding mechanisms to become contaminated with moisture that can freeze or rust the mechanism, or with rocks, dust or other debris that can create resistance or jam the unit completely. As the sliding mechanism is located atop the tractor vehicle, it is effectively out of reach on larger mine trucks and therefore it is difficult for an operator to inspect it prior to or during operation, thereby making it inconvenient to keep the mechanism free of debris. 
         [0005]    Some prior art mechanisms get stuck without the introduction of contaminants. Simple sliding mechanisms comprised of a rectangular plate in a slightly larger rectangular track can become jammed as a result of misalignment of the two pieces. The fact that such units are continually connected and disconnected from a very large pieces of equipment and that they carry a very large load increases the risk of bending and distortion of the sliding track components. 
         [0006]    It is therefore an object of the present invention to provide an articulation mechanism for a hydraulic removable gooseneck that avoids the jamming that characterizes sliding fifth wheel and gooseneck assemblies. 
         [0007]    It is a further object of the invention to provide a connection between the gooseneck and the tractor vehicle that provides three degrees of freedom of movement between them in the low bed mode and that restricts those three degrees of freedom in the vehicle towing mode. 
         [0008]    The transition between the low bed mode and the vehicle towing mode involves moving the gooseneck between a forward and an aft position on the tractor vehicle. The transition typically involves considerable stresses on the sliding mechanism and on the sub-frame that is installed on the tractor vehicle bed to support the gooseneck and the associated components. It is a further object of the present invention to minimize the stresses on the articulation mechanism and sub-frame of a gooseneck during the transition between the low bed mode and the vehicle towing mode. 
         [0009]    As the gooseneck connection is detachable from the low bed trailer deck, a locking mechanism is usually provided to secure the hitching mechanism when the low bed deck is hitched to the gooseneck and hitch assembly. Providing such a lock is prudent from a safety standpoint, but the lock mechanism does not provide significant additional strength to the gooseneck connection. Some prior art systems attempt to assist the gooseneck in connecting to the trailer by applying a pulling force during connection to bring the two parts of the connection (trailer and tractor vehicle) closer together to complete a snug connection. That is not easy to achieve with the large equipment involved unless the design, manufacturing, operation, and environment are very specific. In practice, attempts to force the gooseneck and trailer together result in additional stresses being added to the connection and part failure, due in part to the fact that the size and power of the lock assemblies are significantly less than those of the gooseneck and trailer (especially a loaded trailer). 
         [0010]    It is therefore a further object of the present invention to provide a simple but effective locking mechanism for a gooseneck to low bed deck hitch. 
         [0011]    These and other objects of the invention will be better understood by reference to the detailed description of the preferred embodiment which follows. Note that not all of the objects are necessarily met by all embodiments of the invention described below or by the invention defined by each of the claims. 
       SUMMARY OF THE INVENTION 
       [0012]    The present invention avoids the use of a sliding gooseneck assembly to transition between forward and afterward positions by instead pivoting the base of the gooseneck at the end of a pivoting member so that the base of the gooseneck travels along an arcuate path. This reduces the point of moving contact between the tractor and the gooseneck to one or more coaxial pivot points rather than through a slide track, thereby minimizing the opportunity for jamming through debris or other contaminants. 
         [0013]    According to the preferred embodiment, a pivoting arm assembly is mounted to the tractor and the forward end (base) of the gooseneck is attached to a portion (preferably the end) of the pivoting arm assembly that undergoes arcuate travel. 
         [0014]    Apart from avoiding the problems inherent in the use of sliding mechanisms in contaminant-laden environments, the pivoting arm assembly articulation enables the rear of the gooseneck and hitch assembly to be supported on the ground while the gooseneck is moved between the two positions. This significantly decreases the load that the articulation mechanism needs to support. 
         [0015]    In another aspect, the invention comprises a locking mechanism for the deck hitch of a detachable gooseneck trailer. The locking mechanism comprises a locking member that pivots from a pivot point that is rearward of an afterward-opening hitch recess. In a more particular aspect, the hitch recess is provided on a hitch assembly that is pivotally attached to the end of the gooseneck. In a further aspect, the locking member has a substantially flat surface for abutting a hitch shaft of a trailer deck. 
         [0016]    In a further aspect, the locking member is actuated by a hydraulic cylinder that actuates a rotating member. A second link is pivotally attached to the rotating member and to the locking member. When the locking member is in the lock position, three pivot points are substantially aligned: the pivot point of the rotating member, the pivot between the rotating member and the second link, and the pivot between the second link and the locking member. The aligned pivots provide mechanical resistance to articulation of the locking member thereby offering a failsafe if the hydraulic cylinder fails. 
         [0017]    In another aspect of the invention, the forward end of the gooseneck is pivotable in relation to the tractor about a vertical axis, about an axis that is transverse to said tractor vehicle and about a longitudinal axis of the tractor. 
         [0018]    The foregoing was intended as a broad summary only and of only some of the aspects of the invention. It was not intended to define the limits or requirements of the invention. Other aspects of the invention will be appreciated by reference to the detailed description of the preferred embodiment and to the claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]    The invention will be described by reference to the detailed description of the preferred embodiment and to the drawings thereof in which: 
           [0020]      FIG. 1  is a side elevation of the preferred embodiment of the invention, showing a tractor vehicle, gooseneck and hitch assembly and a low bed deck, in low bed mode; 
           [0021]      FIG. 2  is a side elevation of the preferred embodiment showing a tractor vehicle, gooseneck and hitch assembly and towed vehicle, in vehicle towing mode; 
           [0022]      FIG. 3A  is an oblique projection of the gooseneck of the preferred embodiment; 
           [0023]      FIG. 3B  is a plan view of the gooseneck of the preferred embodiment; 
           [0024]      FIG. 4A  is a plan view of the tractor vehicle and associated structures of  FIG. 2 ; 
           [0025]      FIG. 4B  is a plan view of the tractor vehicle and associated structures of  FIG. 1 ; 
           [0026]      FIG. 5A  is a vertical section taken along line  5 A- 5 A of  FIG. 4A ; 
           [0027]      FIG. 5B  is an exploded view of the pivot plate, base plate and forward portion of the gooseneck; 
           [0028]      FIG. 6  is a vertical section of the tractor vehicle taken along line  6 - 6  of  FIG. 4B , with the gooseneck removed; 
           [0029]      FIG. 7A  is a vertical section of the gooseneck taken along line  7 A- 7 A of  FIG. 3B ; 
           [0030]      FIG. 7B  is a front view of the forward portion of the gooseneck; 
           [0031]      FIG. 8A  is a plan view of the pivot plate; 
           [0032]      FIG. 8B  is a side view of the pivot plate; 
           [0033]      FIG. 9A  is a plan view of the pivoting arm assembly; 
           [0034]      FIG. 9B  is a view taken along line  9 B- 9 B of  FIG. 9A ; 
           [0035]      FIG. 10  is the view of  FIG. 6 , but with the pivoting arm assembly in an intermediate position between the low bed mode and the vehicle towing mode; 
           [0036]      FIG. 11  is the view of  FIGS. 6 and 10 , but with the pivoting arm assembly in position for the vehicle towing mode; 
           [0037]      FIG. 12A  is a plan view of the sub-frame; 
           [0038]      FIG. 12B  is a view taken along lines  12 B- 12 B of  FIG. 12A ; 
           [0039]      FIG. 13A  is a plan view of the support arm assembly; 
           [0040]      FIG. 13B  is a side elevation of the support arm assembly; 
           [0041]      FIG. 14A  is a vertical section of the gooseneck and hitch assembly with the locking paddle in lock/latched position; 
           [0042]      FIG. 14B  is a vertical section of the gooseneck and hitch assembly with the locking paddle in unlocked position; 
           [0043]      FIG. 15  is a rear view of the hitch assembly only taken from approximately lines  15 - 15  of  FIG. 14B . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0044]    In the following description, the preferred embodiment of the invention will be described. However, it will be appreciated that alternative embodiments that do not necessarily embody the same constructional and design features may be implemented while still applying the broader principles of the invention. 
         [0045]    As is the case for many prior art detachable gooseneck trailers, the tractor, gooseneck and hitch assembly according to the preferred embodiment may be operated in two modes: the low bed mode illustrated in  FIG. 1  and the vehicle towing mode illustrated in  FIG. 2 . 
         [0046]    The base of a gooseneck  10  is mounted behind the cab of a tractor vehicle  12 . The gooseneck  10  terminates at a pivot  14  to which a hydraulically-actuated hitch assembly  16  is pivotally attached. 
         [0047]    In low bed mode ( FIG. 1 ), the gooseneck  10  is in an afterward, rearmost position relative to the tractor vehicle, defining a space L between the rear of the hauling vehicle  12  and the front of the low bed  18 . This allows clearance for rotation (about a vertical axis) between the low bed deck and the tractor vehicle. The hitch assembly  16  is designed to be attached to a horizontal hitch pin  20  provided on the front of the low bed  18 , and a bearing surface  22  of the hitch assembly is brought into contact with a bearing portion  24  of the low bed at a position aft of the hitch pin  20 . As is known, this enables the gooseneck to raise the front of the low bed deck  18  by applying torque between the hitch pin  20  and the bearing portion  24  of the low bed deck. 
         [0048]    In vehicle towing mode ( FIG. 2 ), the gooseneck  10  is in a forward position such that the vertical portion  26  of the gooseneck is tucked into the rear of the tractor vehicle in comparison to distance L in the low bed mode. This allows support arm  92  to provide the lifting force to lift the towed vehicle, and “captures” the neck, restricting its three degrees of freedom. The towed vehicle is hitched to a vertical hitch pin  28  that is provided at the rear of the hitch assembly  16 . 
         [0049]    Referring to  FIGS. 2 ,  3 A,  3 B and  4 A, the gooseneck  10  consists of two parallel L-shaped members  30 ,  31  each comprising a generally horizontal portion  32  and a vertical portion  34 . Cross-members  36 ,  38  and  40  and shaft  42  extend between the L-shaped members  30 ,  31 . 
         [0050]    As best appreciated by reference to  FIG. 5A , the forward end of the gooseneck  10  is supported by an articulated support assembly  44 .  FIG. 5B  provides an exploded view of a pivot plate  46  and a base plate  47  as well as longitudinal axis pivot pins  49 .  FIG. 6  is a vertical section taken along lines  6 - 6  of  FIG. 4B  but wherein the gooseneck  10  has been removed. The gooseneck support assembly  44  consists generally of a pivot member in the form of pivot plate  46 , a pivoting arm assembly  48  and a hydraulic cylinder  50 . One end of hydraulic cylinder  50  is secured to a forward cross-member  52  of a sub-frame  54  (which will be described in more detail below). The other end of the cylinder  50  is attached to a lug on central cross-member  56  of the pivoting arm assembly  48 . 
         [0051]    The pivot plate  46  is shown in more detail in  FIGS. 8A and 8B . A vertical pivot pin  58  extends centrally of a plate  60 , along a transverse axis of the tractor vehicle. The forward end of the gooseneck  10  is pivotally engaged to the pivot pin  58  enabling rotation of the gooseneck in the plane of plate  60 , i.e. within the horizontal plane and about a vertical axis (designated as the z-axis in  FIG. 5B ). The bottom of the plate  60  includes two opposed flanges  62  each of which has a pivot aperture  64 . Pivot apertures  64  are threaded by pivot shaft  66  of pivoting arm assembly  48 , thereby enabling pivoting of the gooseneck in the vertical plane about an axis that is transverse to the tractor vehicle (designated as the y-axis in  FIG. 5B ). 
         [0052]    Referring to  FIGS. 9A and 9B , pivoting arm assembly  48  includes two arms  68 ,  70  joined by a central cross-member  56 . Pivot shaft  66  extends between arms  68 ,  70 . Each pivoting arm  68 ,  70  includes a pivot aperture  72  for receiving pivot pins  76  attached to sub-frame  54 . Through such attachment, the pivot axis for the pivoting arm assembly is fixed in relation to the tractor vehicle. A hydraulic cylinder  73  actuates the extension or retraction of lock pins  75  to lock the rotation arm assembly  48  into position prior to use, as will be described below. 
         [0053]    Referring to  FIG. 5B , pivoting of the gooseneck about the longitudinal axis of the tractor vehicle (the axis designated as x-axis in  FIG. 5B ) is enabled by horizontal pivot elements in the form of pins  49  mounted in bearings  51 ,  53  within lugs  55  that extend upward from a base plate  47 . 
         [0054]    The support assembly  44  in conjunction with the x-axis pivot pins  49  provide three degrees of freedom of movement of the gooseneck: pivoting about an axis that is longitudinal to the tractor vehicle, pivoting about an axis that is vertical and pivoting about an axis that is transverse to the tractor vehicle. 
         [0055]    In operation, when cylinder  50  is fully extended as shown in  FIG. 6 , pivoting arm assembly  48  is pivoted to the rearmost position, corresponding to the low bed mode of  FIG. 1 .  FIG. 10  shows the cylinder  50  with its piston partially retracted and pivoting arm assembly  48  in an intermediate position. When the piston is fully retracted ( FIG. 11 ), pivoting arm assembly  48  is in its forward most position corresponding to the vehicle towing mode of  FIG. 2 . This arcuate motion arrangement avoids any slide track that might be contaminated by debris and it limits the moving connection between the tractor vehicle and the gooseneck to the two pivots points  67 ,  69  (see  FIGS. 6 and 9A ) on the pivoting arm assembly  48 . 
         [0056]    Sub-frame  54  ( FIGS. 12A and 12B ) provides the interface between the tractor vehicle and the gooseneck support assembly and the support arm assembly  92 . Sub-frame  54  comprises two generally L-shaped members  82 ,  84  connected by cross-members  86 ,  88  and  90 . Pivot pin  76  is threaded through pivot apertures  72  of pivoting arm assembly  48 . Shaft seats  85 ,  87 ,  89  and  91  provide seats for the pivoting arm of arm assembly  48  in its forward most and rearmost positions. 
         [0057]    The aft portion of the gooseneck  10  is supported by a support arm assembly  92  ( FIGS. 13A and 13B ) consisting of two support arms  94 ,  96  joined at the rear by a cross-tube  98 . Cylinder mounting lugs  100  are provided at each end of cross-tube  98 . The forward ends of support arms  94 ,  96  are pivoted on cross-member  88  of sub-frame  54 . Referring to  FIGS. 11 and 5A , support arm assembly  92  is used to selectively raise or lower the gooseneck  10  by means of a pair of hydraulic cylinders  102  first ends of which are secured to cross-member  90  of sub-frame  54  and the other ends of which are attached to lugs  100 . Support arm assembly  92  is used to raise the gooseneck  10  when in vehicle towing mode to lift the front of the towed vehicle. It also supports the gooseneck and hitch assembly when the low bed trailer deck is not hitched. 
         [0058]    The hitch assembly  16  will now be described by reference to  FIGS. 14A ,  14 B and  15 . Two parallel vertical arms  110 ,  112  are joined at their base by an aft ward extension  114 . Parallel arms  110 ,  112  are also joined by cross member  111  and by upper web  113 . Afterward-opening C-shaped recesses  117 ,  119  at the bottom of each arm  110 , 112  accommodate a horizontal hitch shaft  20  on the low bed deck. Hydraulic cylinder  116  pivots the hitch assembly  16  about shaft  42  at the end of the gooseneck. Preferably a pair of side by side cylinders  116  is provided. 
         [0059]    When the user wishes to hitch the tractor vehicle to a low bed deck, if the gooseneck is not already in the rearmost position shown in  FIG. 1 , the piston of cylinder  50  is extended to cause pivoting arm assembly  48  to rotate toward the rearmost position until extensions  13 ,  15  of shaft  66  of the pivoting arm assembly are seated in seats  87 ,  91 . As the pivoting arm assembly  48  supports the pivot plate  46  which in turn supports the forward end of the gooseneck, the forward end of the gooseneck undergoes an arcuate movement  49  from the forward most to the rearmost position. Locking pins  75  are then engaged into apertures  77  provided in the seats  87 ,  91 . Movement of the locking pins  75  is actuated by hydraulic cylinder  73 . Preferably, movement of the gooseneck from the forward to the aft position is done with the base of the hitch assembly resting on the ground and with the tractor vehicle in neutral, so as to minimize stress on the gooseneck support assembly. The gooseneck support arm assembly  92  is then positioned to provide an appropriately low clearance for the hitch assembly  16  to engage the hitch shaft  20  of the low bed. Once properly positioned, the tractor vehicle is backed up to the low bed so as to fully engage the recesses  117 ,  119  about the hitching shaft  20 . Once the hitching shaft is fully seated in the recesses  117 ,  119 , a locking member  120  is rotated downward to the lock position. 
         [0060]    Referring to  FIG. 14A , a locking member in the form of paddle  120  is pivoted from a point  122  on hitch assembly  16  that is located aft of the recesses  117 ,  119 . The forward end of paddle  120  includes a substantially flat surface  124  for abutting the aft side of the hitching shaft  20  to retain hitching shaft  20  in recesses  117 ,  119  when the trailer is being towed. A cylinder  126  actuates pivoting of the paddle through an over center cam rotating member  128  pivoted on pivot shaft  42 . Over center cam member  128  is pivotally attached to link member  125  at a point  127  and is pivotally attached to the piston of cylinder  126  at a point  129  that is angularly displaced in relation to point  127 . Link member  125  is pivotally attached at point  131  on a lug on paddle  120 . When the piston of cylinder  126  is fully extended, paddle  120  is pivoted to engage the hitching shaft  20  and the over center cam member  128  is rotated to a latched position in relation to the paddle. 
         [0061]    When the paddle  120  is in the lock position, three pivot points are substantially aligned: the pivot point  42  of the over center cam member, the pivot  127  between the over center cam member  128  and the link member  125 , and the pivot  131  between the link member  125  and the paddle  120 . The aligned pivots provide mechanical resistance to articulation of the paddle thereby offering a failsafe if the hydraulic cylinder fails. 
         [0062]    The piston of cylinder  116  is then extended to pivot the hitch assembly  16  about the pivot  42  causing bearing surface  22  to bear down against the surface of the low bed at point  24  that is aft of the hitching shaft  20 . This raises the front of the low bed and provides a secure hitch. Once the deck is properly secured, support arm assembly  92  is lowered to its lowest position to allow full play to the vertical, longitudinal and transverse axis pivotability of the forward end of the gooseneck. 
         [0063]    The low bed deck  18  may be disengaged from the gooseneck assembly by retracting the piston of cylinder  116  to relieve the torque between the hitching shaft  20  and point  24  on the deck, retracting the piston from cylinder  126  to disengage the paddle lock, raising the support arm  92  to support the gooseneck and driving the tractor vehicle away from the deck  18 . 
         [0064]    In order to attach the tractor vehicle and gooseneck assembly to a vehicle to be towed, pivoting arm assembly is rotated to the forward most position, with extensions  13 ,  15  of shaft  66  seated in seats  85 ,  89  of sub-frame  54 . This moves the vertical portion of the gooseneck forward toward the rear of the tractor vehicle. Locking pins  75  are engaged into apertures  79  in seats  85 ,  89 . Preferably, this is done with the tractor vehicle in neutral and the base of the hitch assembly resting on the ground (support arm assembly  92  fully lowered). Once the gooseneck is in the forward position, support arm  92  is then raised to lift the hitch  16  just clear of the ground. The tractor vehicle is then reversed to position the vertical hitch pin  28  under the vehicle to be towed. Support arm assembly  92  is then raised to raise the gooseneck and the attached hitch assembly and to lift the front end of the towed vehicle. Once supported by support arm  92 , gooseneck articulation is restricted in the x-axis by arm  92  bearing on gooseneck members  30 ,  31  and in the y-axis by the 3 points of contact (arm  92  on members  30 ,  31 , and plate  47  on plate  60 ) and in z-axis by the flanges  133 ,  135  on the ends of support arm  92 . These flanges capture members  30 ,  31  and restrict z-axis rotation. There nonetheless remain the 3 degrees of freedom inherent in the hitch  28  to allow the required movement between the tractor and the towed vehicle. 
         [0065]    As noted above, in order to effect a transition of the gooseneck and hitch assembly from the low bed mode to the vehicle towing mode, support arm assembly  92  may be lowered fully so that the base of the hitch assembly  16  rests on the ground. The tractor vehicle is then put into neutral gear. The piston of hydraulic cylinder  50  is then retracted to rotate the pivoting arm assembly  48  from the rearmost to the forward most position. As the pivoting arm assembly  48  completes its travel through the arc, the bulk of the weight of the gooseneck and hitch assembly is borne by the ground. As the pivoting arm assembly  48  travels between its two extremes, the tractor vehicle may be urged rearward to track the movement of the pivoting arm assembly. The reverse sequence is used to transition from the vehicle towing mode to the low bed mode. This mechanism and method of transitioning between the two modes presents considerably less stress on the gooseneck support assembly than would be the case by simply articulating the entire weight of the gooseneck and hitch assembly without laying the hitch assembly  16  on the ground. 
         [0066]    The invention therefore provides a mechanism for arcuate travel of the gooseneck support assembly (and therefore the forward end of the gooseneck) that not only limits the ability of contaminants to jam the assembly, but it also provides three degrees of freedom of movement for the gooseneck in relation to the tractor vehicle in low bed mode and restricts those degrees of freedom in vehicle towing mode. The locking member arrangement provides an inherent failsafe for securing the low bed deck hitch shaft into the hitch assembly. 
         [0067]    It will be appreciated by those skilled in the art that the preferred and alternative embodiments have been described in some detail but that certain modifications may be practiced without departing from the principles of the invention.