Abstract:
A lock assembly for selectively latching the pivoting tongue of a steerable trailed vehicle includes an actuator assembly on the vehicle connected by a cable to latch bolt for spring biasing in discrete positions into aligned apertures for enabling and preventing tongue pivoting. The tongue is provided with a winch assembly having a cable attached to the trailed vehicle and operable for raising and lowering the tongue. The tongue includes a hitch assembly having an extendable and pivotable lunette for connection with a proximately located towing vehicle.

Description:
RELATED APPLICATION 
     The present invention is a continuation-in-part application of U.S. Ser. No. 11/834,931 filed on Aug. 7, 2007 and entitled “Lock Assembly For The Tongue Of A Steerable Trailer”. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to trailed vehicles and, in particular, a lock and positioning assembly for the tongue of a steerable trailer. 
     BACKGROUND OF THE INVENTION 
     Trailers having a steerable front wheel assemble responsive to pivoting of the trailer tongue relative to the towing vehicle are available for elongated transport lengths, particularly where the towing vehicle is a load transport vehicle connected to an auxiliary trailer. The steering capability allows the vehicle combination to better navigate off-road tortuous paths. While providing increased maneuverability in forward travel, due to the dual pivot at the connecting hitch and the front wheels, accurately backing up to and hitching with the trailer is extremely difficult. 
     Such combinations are common in military applications. One such application includes the military M989A1 heavy expanded mobility ammunition trailer used by the military for the transport of missile pods and munitions, palletized and unpalletized loads, fuel pods and bladders, and the like. The trailer is hauled by substantial prime mover vehicles including the HEMTT series truck and the Armored Vehicle-Mounted Rocket Launcher. During operations it is oftentimes necessary to accurately position the trailer. To overcome the inherent limitations of the dual pivots, the M989A1 trailer is provided with a manually operated lock bolt located beneath the trailer front wheel assembly, which requires an operator to crawl under the vehicle and insert a lock bolt into and out of holes that are aligned when the trailer tongue is in the longitudinal straight ahead position. Achieving such alignment requires truck movement posing a danger to the bolt operator. Even slight misalignment can create a hole location mismatch preventing insertion or removal. Further difficulties are encountered in hitching the trailer with the truck. The tongue is extremely heavy, around 200 lbs. and under current regulations requires two or more personnel to raise the tongue while the truck backs up to the trailer. The hitch component must be closely located to the hitching location inasmuch as the trailer tongue and the weighted wheel assembly are relatively immobile and can at best be only limitedly moved to compensate for errors truck positioning. The additional time for manually handling and positioning poses additional safety risks to the personnel. 
     It would accordingly be desirable to provide a locking mechanism for locking and unlocking a steerable wheel trailer tongue that can be readily installed on existing vehicles for selective automatic operation without risk to the operator and to provide a positioning assembly for limiting the personnel and time for establishing a hitched condition between the truck and trailer. 
     SUMMARY OF THE INVENTION 
     This present invention provides a lock assembly for selectively latching the pivoting tongue of a steerable trailed vehicle. The lock assembly includes an actuator assembly on the vehicle accessible by an operator from the side of the vehicle and connected by a cable to latch bolt for spring biasing in discrete positions into aligned apertures for enabling and preventing tongue pivoting. More particularly, the trailed vehicle includes a frontally projecting arm having a first axial hole that axially registers with a second axial hole in the trailer chassis when the tongue is in a straight ahead position. A latch assembly supported on the arm includes a slidable latch bolt moveable between an unlatched position in the first hole allowing the pivotal movement of the tongue and a latched position in both holes preventing the pivotal movement of the tongue. An actuator assembly mounted at the front and safely accessible from the side of the trailer includes a shift member moveable between a first position and a second position. A cable operatively interconnects the latch bolt and the shift member for moving the latch bolt to the unlatched position when the shift member is in the first position and for moving the latch bolt to the latched position when the shift member is in the second position. A first spring engages the shift member and is effective under biasing to move the shift member to the first position. A second spring engaging said shift member is effective under biasing to move the shift member to the second position. A manually operated actuator handle selectively biases the springs. The actuator member in a retraction position biases the first spring whereby the shift member and cable move the bolt from the unlatched position to the latched position when the holes are aligned. The actuator member in an extension position biases the second spring whereby the shift member and cable move the bolt from the latched position to the unlatched position when the holes are aligned. Necessary movement of the truck movement is thus without risk to the operator. 
     In another aspect, the lock assembly includes a first lock for selectively maintaining the actuator member in the retraction position and a second lock for selectively maintaining the actuator member in the extension position. 
     In another aspect, the lock assembly the actuator comprises a housing and the shift member includes a shaft axially supported by the housing. The shaft includes first and second enlarged axially spaced stop surfaces, and the first spring engages and biases the first stop surface and the second spring engages and biases the second stop surface. The first stop surface engages one end of the housing in the unlatched position and the second stop surface engages another end of said housing in said latched position. An axial slot is formed in the housing and a sleeve slidably supported on the shaft. A handle extends through the slot and is connected with said sleeve. The handle is axially shifted to one axial end of the slot to establish the biasing on the first spring and axially shifted to another axial end of the slot to establish the biasing on the second spring. As a result, the latching conditions are achieved automatically without operator intervention. 
     In a further aspect, the invention provides a positioning assembly for establishing a hitch condition with a trailed vehicle including a trailer chassis having a steerable front wheel assembly including a trailer tongue pivotally connected thereto for pivotal movement about a horizontal axis, said tongue being operable to rotate said front wheel assembly about a vertical axis; a lock assembly for selectively locking and unlocking pivotal movement of the tongue and front wheel assembly about said vertical axis; and winch assembly mounted on said tongue having a cable having an end for attachment to the trailer, said winch assembly being manually operable to extend and retract said cable to selectively change the pivotal position of said tongue. The tongue may include a hitch assembly on an outer end of said tongue, said hitch assembly including a hitching component for attachment to a towing vehicle that is extendable and pivotable with respect to said tongue for establishing a hitched condition with a proximately located towing vehicle. 
     Accordingly, it is an object of the invention to provide a tongue lock assembly for a steerable trailer that may be readily installed and actuated automatically without risk to the operator. 
     Another object is to provide a steerable trailer tongue lock that that may be conditioned for automatic actuation when the trailer tongue is properly aligned. 
     A further object is to provide a lock assembly for a steerable trailer that actuates under selective spring biasing to move between latched and unlatched positions without operator assistance. 
     Yet another object is to provide a trailer tongue positioning assembly for assisting personnel in quickly and safely establishing a hitched condition with a proximately located trailer. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other advantages of the present invention will become apparent upon reading the following written description taken in conjunction with the accompanying drawings in which: 
         FIG. 1  a fragmentary front view of a steerable trailer provided with a tongue lock assembly; 
         FIG. 2  is a front view of the trailer of  FIG. 1 ; 
         FIG. 3  is a side view of the trailer of  FIG. 1 ; 
         FIG. 4  is a side view of the lock assembly for  FIG. 1 ; 
         FIG. 5  is a front view of the actuator assembly for the lock assembly in the bolt retraction position; 
         FIG. 6  is a front view of the actuator assembly for the lock assembly in the bolt insertion position; 
         FIG. 7  is a schematic view of the lock assembly in the preparatory bolt retraction position; 
         FIG. 8  is a schematic view of the lock assembly in the full bolt retraction position; 
         FIG. 9  is a schematic view of the lock assembly in the preparatory bolt insertion position; 
         FIG. 10  is a schematic view of the lock assembly in the full bolt insertion position; 
         FIG. 11  is a cross sectional view of the actuator assembly; 
         FIG. 12  is a partial front view of the trailer of  FIG. 2  with the tongue in a raised position prior to coupling in accordance with another embodiment of the invention; 
         FIG. 13  is a partial front view of the trailer with the tongue in a lowered position after coupling; 
         FIG. 14  is a partial top view of the trailer of  FIG. 12  with the hitch assembly in a retracted position prior to coupling; 
         FIG. 15  is a partial top view of the trailer of  FIG. 12  is the hitch assembly in an extended swiveled position after coupling; 
         FIG. 16  is a fragmentary front view of the trailer of  FIG. 12  showing the attachment of the winch connection to the trailer at the lock assembly; and 
         FIG. 17  is a cross section view taken along line  17 - 17  of  FIG. 16 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to  FIGS. 2 and 3 , there is shown a steerable trailer  10  provided with a tongue lock assembly  12  in accordance with a preferred embodiment of the invention. A preferred trailer is a M989A1 heavy expanded mobility ammunition trailer used by the military for the transport of missile pods and munitions, palletized and unpalletized loads, fuel pods and bladders, and the like. The trailer  10  includes a pair of front wheel assemblies  14  supported on the trailer chassis that are pivoted by a conventional steering linkage, not shown, is response to pivotal movement of a trailer tongue  16  imparted by movement of a towing vehicle. To enable controlled rearward movement of the trailer and altered towing characteristics, the lock assembly  12  is selectively used to lock the tongue in a forward straight ahead position or to unlock the tongue for steering pivotal movement. Referring additionally to  FIG. 1 , the lock assembly  12  comprises a control assembly  20  carried at the front of the trailer beneath a spare tire mount assembly  22  including spare tire  23 , and a latch bolt assembly  24  carried beneath the tongue support assembly  26  and interconnected by a control cable assembly  28 . The actuator assembly  20  is safely accessible by standing operating personnel from the side of the trailer. 
     More particularly and as shown in  FIGS. 1 and 4 , the control assembly  20  is carried on a top base or platform  30  of the spare tire mount assembly  22 . The control assembly  20  is releasably connected to a support post  32  of the mount assembly  22  by a clamp assembly  36 . The control assembly  20  includes a base plate  40  engaging the top surface of the platform  30 . The base plate  40  has a downwardly and inwardly projecting front flange  42  that compressively engages the front edge of the platform  30  upon adjustment of the clamp assembly  36 . A lock bolt actuator assembly  44  and a cylindrical cable guide sleeve  46  for routing the cable assembly  28  are attached to the base plate  40 . A rectangular front face plate  48  is connected to the base plate  40  and actuator assembly  44  at front thereof. 
     Referring to  FIG. 11 , the actuator assembly  44  comprises an outer cylinder  50  axially slidably housing an actuator spindle  52 . The spindle  52  includes a cylindrical shaft  54  having axially spaced enlarged cylindrical stop collars  56 ,  58 . The outer ends of the shaft  54  extend through apertures in circular end plates  60  connected at the outer ends of the cylinder  50 . The spacing between the outer surfaces of the stop collars  56 ,  58  is less than the spacing between the inner surfaces of end plates  60  such that the spindle  52  can reciprocate an axial distance “D” equal to the bolt travel of the lock bolt assembly as described below. An apertured cylindrical stop sleeve  62  is slidably carried on the shaft  54  intermediate the stop collars  56 ,  58 . Helically coiled compression springs  64 ,  66  surround the shaft  54  between the stop collars  56 ,  58  and the stop sleeve  62 . One of the stop collars is separately assembled to facilitate assembly. Referring additionally to  FIG. 1 , the cylinder  50  and the face plate  48  include frontally opening rectangular slots  64 . A radially extending actuator handle  69  is attached to the stop sleeve  62 , whereby the stop sleeve  62  may be shifted within the ends of the slots  64  from the neutral position of  FIG. 1  to the bolt retraction position of  FIG. 4  or the bolt insertion position of  FIG. 5 . In the neutral position, no active biasing is presented to the spindle and the same remains in the selected position. 
     Referring to  FIGS. 5 and 6 , an axially spaced pair of generally triangular stop plates  70 ,  72  are pivotally attached to the face plate  48  by fasteners  74 . The plate includes projecting pins  75  for manual rotation to the stop positions. The stop plate  72  is rotated to the stop position shown in  FIG. 5  to maintain the actuator handle  69  in the left hand stop position for the bolt retraction as described below. Alternatively, the stop plate  70  is rotated to the stop position shown in  FIG. 6  to maintain the actuator handle  69  in the right hand position for bolt insertion. “Up” and “Down” indicia, are provided on the face plate to denote the insertion and retraction positions respectively. 
     Referring to  FIG. 1 , the control cable assembly  28  is a conventional construction having an outer sheath  80  slidably supporting a control cable  82 . At the actuator assembly, one end of the sheath is connected to a bracket  84  attached to the base plate and the associated end of the cable is connected by the projecting end of the spindle shaft  54  by coupling  86 . The control cable assembly is inserted through the cylindrical opening in the guide  48  for routing the cable assembly  28  to the latch assembly  24 . 
     The trailer tongue  16  is pivotally supported at a lower end on a transverse front chassis member including a frontal projecting plate or nose  90 . A frontally projecting arm  92  is operatively connected for concurrent rotation with the trailer tongue. Vertical indicia may be provided on the front surfaces of the arm  92  and note  90  to indicate when the tongue is in the straight ahead position. Holes  96 ,  98  are formed in the arm  92  and nose  90 , respectively that are axially aligned in the straight ahead position. 
     The latch assembly  24  comprises a cylindrical housing  100  attached to the lower surface of the arm  92  and slidably supporting a cylindrical latch pin or bolt  102  axially aligned with the hole  96 . In the down or bolt retraction position, the upper end of the bolt  102  is resident in the hole  96  in the arm  92  and the tongue  16  and arm  92  can pivot relative to the trailer during movement. In the up or bolt insertion position, the upper end of the bolt  102  is also resident in the hole  98  in the nose  90  and the trailer tongue and arm are latched against pivotal movement relative to the trailer. 
     A downwardly opening slot  104  is formed in the housing  100 . An actuator arm  106  extends through the slot and has an inner end connected to the bolt  102 . The outer end of the control cable  82  is connected to the actuator arm  106 . The outer end of the sheath  80  of the cable assembly  28  is supported by a horizontal bracket  108  attached to the housing  100 . Accordingly, the bolt  102  is shifted by the cable  82  between the positions in response to actuator movement. 
     In operation,  FIGS. 7 and 8  illustrate movement to unlock the tongue from the preparatory unlatched condition ( FIG. 7 ) to the completed or full unlatched condition ( FIG. 8 ). To establish the preparatory unlatched condition, the actuator handle  69  is shifted to the left whereby the spring  64  is compressed to establish an extending bias on the stop collar  56  and the control cable. At this position, preferably the stop plate  72  is rotated to the position shown in  FIG. 5  thereby maintaining the handle position. Even with apparent alignment of the vertical indicia, there are generally sufficient shear forces on the lock bolt to resist retraction. To overcome any resistance, the towing vehicle is forwardly or rearwardly moved, readily resulting in momentary alignment allowing the bolt  102  to shift to the  FIG. 7 , the completed unlatched condition. The stop plate  72  may remain in the lock position to prevent any tendency for the bolt to shift during transit toward the latched condition. 
       FIGS. 9 and 10  illustrate movement to lock the tongue from the preparatory latched condition ( FIG. 9 ) to the completed latched condition ( FIG. 10 ). To establish the preparatory latched condition, the actuator handle  69  is shifted to the right whereby the spring  66  is compressed to establish a retracting bias on the stop collar  58  and the control cable and compressive engagement between the bolt  102  and the lower surface of the nose  90 . At this position, preferably the left stop plate  70  is rotated to the position shown in  FIG. 6  thereby maintaining the handle position. At this position, the holes  96  and  98  in the arm  92  and nose  90  are circumferentially misaligned. To overcome the misalignment, the towing vehicle is forwardly moved, readily resulting in momentary alignment of the holes allowing the bolt to shift automatically upwardly to the  FIG. 8  latched condition. The stop plate may remain in the lock position to prevent any tendency for the lock bolt to shift during transit toward the latched condition. 
     The present invention thus provides a tongue lock apparatus that can be used on both existing and new trailers to achieve safely the selective latching of the trailer tongue to enable and disable tongue pivoting. The components may also be alternatively located to provide safe actuation and tongue latching. 
     Referring to  FIG. 12 , to increase the safety and flexibility in coupling the hitching component, hitch ball  116 , of the towing vehicle in a hitching condition with the trailer using a single operator, the trailer  120  as above described is provided with a positioning assembly  122  including a winch assembly  124  on the top surface of the tongue  126  and a telescoping and swiveling hitch assembly  128  on the outer end of the tongue  126 . The inner end of the tongue  126  is pivotally connected to the steerable wheel assembly  130  at a pivotal connection  132  whereby the tongue is independently pivotable about a horizontal axis, and cojointly pivotable with the wheel assembly  130  about a vertical axis  134 . 
     Referring additionally to  FIG. 13 , the winch assembly  124  comprises a cable spool carrying a cable  140  and having a manually operable crank arm  141  for rotating the cable spool through a drive gear assembly to thereby extend or retract the cable  140 . A suitable winch assembly is commercially available from Tern Inc. as product no. M40442PB, which is a spur gear driven winch using a wire rope cable. Referring to  FIGS. 16 and 17 , the free end of the cable  140  is provided with hook  142  that is attached to cross pin  144  carried by laterally spaced forwardly projecting brackets  146  mounted on the front flange  42  of the lock assembly  12 , as described above. Alternatively, the attachment of the cable end may be at any fixed location at the front of the trailer chassis sufficiently above the pivotal connection  132  to provide a lifting angle suitable for the winch assembly to raise and lower the tongue. The cable end may be provided with any connector arrangement suitable for releasable attachment to the trailer chassis. For trailer of the above described type, the tongue is quite bulky and heavy, 4 feet or more in length and weighing around 200 lbs. Normally at least two personnel are required regulations to hitch or unhitch the tongue from the towing vehicle. This presents handling conditions that can result in personnel and equipment injuries. With the winch assembly  124 , a single operator can readily and safely raise and lower the tongue when and as required during operations. 
     The weight of the tongue and the weight of the trailer chassis on the wide tread front wheel assembly also make it difficult to maneuver the tongue for coupling the hitching components, thereby putting a premium on accurately positioning the towing vehicle hitch component. To reduce the necessity for accurate positioning of the towing vehicle and enable hitching when proximate positioning is achieved, the telescoping and swiveling hitch assembly  128  is provided, preferably as described in my U.S. Pat. No. 7,293,791 and hereby incorporated by reference. Referring to  FIGS. 14 and 15 , the hitch assembly  128  includes a front assembly  150  that is pivotally and telescopically connected to a base assembly  152  mounted on the front end of the tongue  126 . The front assembly  150  includes a hitch lunette  154  that is conventionally coupled in a hitched condition to the hitch ball  116  on the towing vehicle  118 . The front assembly  150  includes a rearwardly extending tow bar  160  that is slidable and pivotable with respect to an internal cavity in the base assembly when a latch assembly  162  is released. Further details of operation are detailed in the above patent. Accordingly, the lunette  154  may be selectively extended and pivoted, in combination with the winch assembly  124 , to position the lunette at coupling condition with the hitch ball. When the lunette  154  is positioned above the hitch ball, the winch assembly  124  is actuated to lower the tongue  126  to a coupling position. Thereafter, the cable  40  is detached and rewound to a stowed condition. Thereafter, when the towing vehicle is moved rearwardly, the tow bar coacts with the housing cavity to align the tow bar in the retracted position, at which location the hitch latch assembly  162  is actuated to lock the assembly. For forward movement, the tongue lock assembly is move to the up position as described above, and the trailer is towed at the steerable wheel assembly. 
     Having thus described a presently preferred embodiment of the present invention, it will now be appreciated that the objects of the invention have been fully achieved, and it will be understood by those skilled in the art that many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the spirit and scope of the present invention. The disclosures and description herein are intended to be illustrative and are not in any sense limiting of the invention, which is defined solely in accordance with the following claims.