Patent Publication Number: US-10328758-B2

Title: Anhydrous ammonia trailer hitch

Description:
FIELD OF THE INVENTION 
     This invention relates to anhydrous ammonia trailers of the type utilized for agricultural fertilizing purposes. More particularly, this invention relates to apparatus adapted for interconnecting such anhydrous ammonia trailers to a towing vehicle or a wheeled agricultural implement. 
     BACKGROUND OF THE INVENTION 
     Towed trailers are commonly subject to rollover accidents which, upon occurrence, may exert extreme torsional forces to the coupling linkage between the trailer and a towing vehicle. Such torsional forces commonly break the linkage, allowing the towed trailer to travel over ground and roadway surfaces independently from and in directions different than the towing vehicle. Incidents of such independent and differently directed trailer travel occurring upon a rollover accident may threaten severe property damage, personal injuries, or fatalities. In order to reduce such risks, flexible safety chains or cables are commonly provided as a backup which further interconnects the trailer and the towing vehicle. In the event of a trailer rollover accident, the flexible backup chains spanning between the trailer and the vehicle are able to violently twist without breaking. The conventionally provided backup safety chains desirably maintain a secure connection between the towing vehicle and its trailer until both vehicles are able to come to a stop. 
     Where the towed trailer constitutes a wheeled anhydrous ammonia tank trailer (which is a subject of the instant invention), toppling and rollover accidents are, as with any trailer, a threat. Accordingly, it remains desirable to equip anhydrous ammonia trailers with safety chains. However, unlike conventional trailers, anhydrous ammonia trailers include a high pressure anhydrous ammonia hose which typically extends forwardly to a forwardly positioned tractor towed fertilizer applicator. Torsional forces experienced during an anhydrous ammonia trailer rollover accident may, in addition to breaking the trailer tongue linkage, break such anhydrous ammonia supply hose, resulting in a violent ejection of anhydrous ammonia vapor and gas. 
     In the event of such dual breakage of a tow tongue linkage and an anhydrous ammonia supply hose, the trailer&#39;s backup safety chains may undesirably fixedly hold the tow vehicle at the vicinity of a potentially lethal expanding cloud of anhydrous ammonia gas. Safety chain holding of the tow vehicle at such location and vicinity may undesirably result in serious gas poisoning or death of the operator of the towing vehicle. In such circumstances, the conventionally used and conventionally needed trailer safety chains are undesirably transformed into a factor causing injury or death. 
     The instant inventive anhydrous ammonia trailer hitch solves or ameliorates the problems and deficiencies described above by specially configuring an anhydrous ammonia trailer hitch to include a linear motion actuator which operatively engages a bolt, which may alternatively retain and release a specially configured release plate component. 
     BRIEF SUMMARY OF THE INVENTION 
     The instant invention is intended for use in towing an agricultural anhydrous ammonia trailer of the type including a fifth wheel chassis, four ground rolling wheels, and an upwardly mounted high capacity tank of agricultural anhydrous ammonia, NH 3 . Agricultural ammonia is utilized as a soil nitrogen enhancing fertilizer, and inhalation of anhydrous ammonia may result in catastrophic lung tissue damage and death. The instant inventive anhydrous ammonia trailer hitch is intended to be protective of such injuries, while continuing to provide conventional modes of vehicle trailering safety. 
     A first structural component of the instant inventive anhydrous ammonia trailer hitch comprises a rigid base. In a preferred embodiment, the base component comprises a rectangular steel plate having forward and rearward faces. According to the orientation of the instant invention, the forward direction is typically understood as being toward towing vehicles, typically comprising a tractor which tows a wheeled fertilizer applicator in train with the anhydrous ammonia trailer. The rearward direction of the instant invention is understood as being toward a towed rearmost anhydrous ammonia trailer and toward a connecting trailer tongue which extends forwardly to join with the inventive hitch. 
     A further structural component of the instant inventive hitch comprises vehicle mounting means which are fixedly attached to and extend forwardly from the base component. In a preferred embodiment, the vehicle mounting means comprise a pin half of a pin and socket joint of a type which is commonly described as a receiver hitch. Other vehicle mounting means such as a clamping bracket which engages a chassis member of an immediately forwardly positioned fertilizer applicator may be provided. 
     A further structural component of the instant inventive hitch comprises a bolt which is mounted to and is operatively connected with the base. In the preferred embodiment, the bolt and its associated connecting structures are adapted for operatively moving the bolt between a latching position and releasing position. In a preferred embodiment, the invention&#39;s bolt component comprises a distal end of an alternatively telescopable and retractable shaft. 
     A further structural component of the instant inventive hitch comprises a release plate having a first eye which is fitted for receiving and engaging with the bolt component. Upon the bolt&#39;s movement to its latching position, the bolt preferably enters and engages the first eye. At its latching position, the bolt resists movements of the release plate away from the bolt and away from the base. 
     A further structural component of the instant inventive anhydrous ammonia trailer hitch comprises a remotely actuatable linear motion actuator. In a preferred embodiment, such actuator comprises a cylinder and piston combination whose piston is fixedly attached to a proximal end of the preferably provided telescoping shaft. Suitably, the remotely actuatable linear motion actuator may alternatively comprise an electric over hydraulic actuator, electric motor driven jack screw actuator, an electric motor driven ball screw actuator, a rack and pinion actuator whose pinion component is electric motor driven, or a heavy duty electric solenoid. Where the linear motion actuator component comprises, as is preferred, a piston and cylinder combination, remote actuation may be provided via hydraulic or pneumatic lines which extend forwardly for valve controlled operation with an operator&#39;s cab. Where the linear motion actuator is electric motor driven, insulated conductors for powering and on/off switching of such motor may alternatively extend forwardly for switched operation within the tow vehicle&#39;s cab. 
     A further structural component of the instant inventive hitch comprises a tongue mount which is fixedly attached to the release plate component, preferably at a rearward aspect of such plate. In a preferred embodiment, the tongue mount comprises a tang half of a tang and clevis joint. In a preferred embodiment, the clevis half of such joint is presented at the forward end of the tow tongue of an anhydrous ammonia trailer. Other suitably substituted tongue mounts comprise a hook half or eye half of a hook and eye trailer hitch, or a common ball receiver trailer hitch. 
     Further structural components of the instant inventive trailer hitch comprise at least a first, and preferably a pair of or right and left safety chain mounts. Such chain mounts are preferably exclusively fixedly attached to or wholly formed with the release plate component. 
     During trailer towing use of the instant inventive anhydrous ammonia trailer hitch, a trailer toppling accident may occur. For example, the rightward wheels of the towed anhydrous ammonia trailer may accidentally fall rightwardly from a ledge or precipice, resulting in rightward toppling of the trailer. In such event, the connection of the invention&#39;s tongue mount to the trailer&#39;s tongue may break, threatening to free the trailer from the forward towing vehicles. In such event, the trailer&#39;s safety chains which are attached to the release plate&#39;s chain mounts may maintain a secure connection between the trailer and the forward towing vehicles, advantageously preventing the overturned trailer from moving in an uncontrolled fashion downslope and away from the tow vehicle. 
     In the further event that the toppling and twisting forces experienced by the trailer during such accident tear away the ammonia supply line, pressurized ejection of NH 3  gas may occur simultaneously with breakage of the trailer&#39;s main towing linkage. Upon such simultaneous breakage, the operator of the trailer&#39;s tow vehicle may easily and conveniently actuate the invention&#39;s remotely actuatable linear motion actuator component to retract the bolt component to its plate releasing position. Upon such bolt actuation, the release plate component along with its safety chain attachments may freely slide away from the base component, allowing the towing vehicle to be driven forwardly with no connection with the trailer. Such remotely actuated disconnect function advantageously allows the operator to utilize the tow vehicle as means for transportation and escape from an expanding cloud of deadly anhydrous ammonia. 
     Accordingly, objects of the instant invention include the provision of an anhydrous ammonia trailer hitch which incorporates structures as described above, and which arranges those structures in relation to each other, in manners described above for the performance of beneficial functions as described above. 
     Other and further objects, benefits, and advantages of the instant invention will become known to those skilled in the art upon review of the Detailed Description which follows, and upon review of the appended drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a preferred embodiment of the instant inventive anhydrous ammonia trailer hitch. 
         FIG. 2  is a front view of the hitch of  FIG. 1 . 
         FIG. 3  shows an anhydrous ammonia tank trailer attached to the instant inventive hitch, the hitch being shown in side view. 
         FIG. 4  presents a plate releasing configuration of the structure of  FIG. 2 , the view showing a releasable component removed. 
         FIG. 5  presents an alternate configuration of the structure depicted in  FIG. 1 . 
         FIG. 6  is a plan view of the instant invention&#39;s releasable component. 
         FIG. 7  presents a further alternate configuration of the structure depicted in  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT 
     Referring now to the drawings, and in particular to Drawing  FIGS. 1-3 , a preferred embodiment of the instant inventive anhydrous ammonia trailer hitch is referred to generally by Reference Arrow  1 . The hitch  1  comprises a base  2  which preferably is configured as a vertically oriented steel plate having front and rear faces. In the view of  FIG. 1 , the rear face of base  2  is oriented toward the viewer. 
     Tow vehicle mounting means are preferably fixedly attached to and extend forwardly from the forward face of the base  2 . In a preferred embodiment, the tow vehicle mounting means component comprise a pin half  38  of a trailer towing pin and socket joint, such joint being commonly referred to as a receiver hitch. Referring to  FIG. 3 , the socket half of such pin and socket joint may comprise a hollow bored receiver  56 , such bore opening rearwardly and receiving a forward extension of the forward end of pin  38 . To secure pin  38  within receiver  56 , laterally alignable eyes  40  and  58  may be provided, and a double sheer slide pin  60  may be extended laterally therethrough. The pin and socket joint  38 , 56  of  FIGS. 1 and 3  is intended as being representative of a reverse configuration of such joint (not depicted within views) in which a socket half of the joint extends forwardly from the base  2 . Where the vehicle mounting means comprise such receiver hitch type pin and socket joint, triangulating gussets  39  are preferably provided to assure a rigid and durable cantilevering extension of the pin  38  from the base  2 . Referring further simultaneously to  FIG. 5 , the invention&#39;s tow vehicle mounting means component may alternatively comprise a clamping bracket assembly including a second forwardly positioned plate  56  which may rearwardly bias against and grasp a rearward chassis member  54 A of a towed implement such as an agricultural fertilizer applicator. 
     In  FIG. 5 &#39;s tow vehicle mounting means alternative, helically threaded bolts  78  securely attach the invention&#39;s rearward hitch components to the chassis member  54 A. All structures appearing in  FIG. 5  which are identified by a reference numeral having the suffix “A” are substantially identical to similarly numbered structures which appear in  FIGS. 1-4 and 6 . 
     A further structural component of the instant inventive hitch comprises a bolt  26  which is securely and movably mounted to the base  2 . In the preferred embodiment, the bolt component is adapted for motion between a latching position and a releasing position. While in its latching position, the bolt  26  extends downwardly through, referring simultaneously to  FIGS. 2 and 6 , a centrally positioned first eye  17  of a release plate  16 . In the preferred embodiment, such first eye  17  is fitted for receiving the distal or lower end  27  of the bolt  26 . The bolt&#39;s latching position is depicted in  FIG. 3  and, as the distal end  27  of the bolt  26  moves downwardly, such distal end may enter and securely engage the at least first eye  17 . 
     The instant inventive trailer hitch preferably further comprises a remotely actuatable linear motion actuator which is connected operatively to the bolt  26  for motion between a latching position (e.g., the bolt&#39;s  FIGS. 1-3  position) and a releasing position (e.g., the bolt&#39;s  FIG. 4  position). In the  FIGS. 1-4  embodiment, the linear motion actuator component is depicted as a two way hydraulic cylinder  30 . Referring in particular to  FIG. 4 , such cylinder  30  has an interior sliding piston  29 , an upper hydraulic fluid volume  33 , a lower hydraulic fluid volume  35 , an upper hydraulic pressure supply line  34 , and a lower hydraulic pressure supply line  36 . Valve controlled actuations of pressurized flow within lines  34  and  36  may alternatively drive piston  29  upwardly and downwardly within cylinder  30 . Such hydraulic actuator alternatively telescopes and retracts the piston shaft/bolt  26  whose upper proximal end is fixedly attached to the piston  29 . The depicted two way hydraulic cylinder  30  is intended as being representative of other suitably substituted remotely actuatable linear motion actuators such as electric over hydraulic actuators, pneumatic cylinders, electric motor driven jack screw actuators, electric motor driven ball screw actuators, electric motor driven rack and pinion actuators, and electric solenoid actuators. 
     A further structural component of the instant inventive trailer hitch  1  comprises a trailer tongue mount which is fixedly attached to the release plate  16 . In a preferred embodiment, the invention&#39;s tongue mount component comprises a tang half  46  of, referring in particular to  FIG. 3 , a clevis and tang joint. The double eared clevis  66  and  68  of such joint is fixedly attached to and extends forwardly from the forward end of a trailer tongue  64  of a wheeled anhydrous ammonia trailer  62 . The tang  46  and clevis  66 , 68  joint is preferably pivotally joined by a slide pin  70  which extends vertically through eyes (not depicted within views) opening at clevis ears  66  and  68 , and opening through eye  48  of tang  46 . The tang component  46  is preferably hingedly mounted to the release plate  16  by means of left and right hinge sleeves  42  and  44  which receive journal axles  41  extending leftwardly and rightwardly from the forward end of tang  46 . The tang configured tongue mount depicted in  FIGS. 1-3  is intended as being representative of other suitably substituted mounts such as a ball receiver, a hook latch, or a hook receiving eye (not depicted within views). 
     A further structural component of the instant inventive trailer hitch comprises at least a first safety chain mount which is fixedly attached to or formed wholly with the release plate  16 . In a preferred embodiment, a pair of or right and left safety chain mounts are provided, such pair comprising a right chain receiving eye  18  and a left chain receiving eye  22 . In the preferred embodiment, such eyes  18  and  22  are formed by loops  20  and  24  which extend respectively rightwardly and leftwardly from rightward and leftward aspects of the release plate  16 . Also in the preferred embodiment, the loops  20  and  24  are “D” configured for additional function as convenient hand holds in assistance of manual carriage of the hitch  1 . 
     Referring simultaneously to  FIGS. 1-3 , the release plate  16  may comprise a tang half of another pin and clevis joint. In the preferred embodiment, such joint has upper and lower clevis ears which are respectively configured as an upper horizontal plate  4  and a lower horizontal plate  14 . Forward ends of such clevis ear plates  4  and  14  are preferably fixedly welded to the rearward face of base plate  2 , and such plates/ears are preferably spaced vertically apart a distance slightly greater than the vertical thickness of the release plate  16 . Such spaced positioning of the plates  4  and  14  advantageously forms and provides a rearwardly opening “U” shaped clevis space  15  into which the release plate  16  may be forwardly slidably received. 
     Upon a forward sliding receipt of release plate  16  within “U” space  5 , as indicated in  FIG. 1 , the upper surface of the lower clevis ear/plate  14  advantageously functions as a shelf for slidable support of such plate. In the preferred embodiment, the upper clevis ear/plate  4  has a second eye  12  which is preferably sized similarly with eye  17  of release plate  16 . The lower clevis ear/plate  14  similarly has a third eye  15  which is denoted in dotted lines upon Drawing  FIG. 2 . 
     The upper clevis ear/plate  4  preferably supports a cylinder bracket  6 , 8 , 10  for abutting support of the mounting plate  28  of cylinder  30 . Helically threaded bolts  32  are preferably utilized for securely attaching such cylinder to bracket  6 , 8 , 10 . In the preferred embodiment, the upper horizontal land  10  of bracket  6 , 8 , 10  is centrally apertured (not within views) for reciprocating telescoping and retracting motions of the invention&#39;s bolt/piston shaft component  26  therethrough. Triangulating gussets  43  are preferably provided for rigidly cantilevering the lower clevis ear/plate  14 , while forwardly welded connections of angled bracket arms  6  and  8  rigidly cantilever the upper clevis ear/plate  4 . 
     Referring to  FIG. 3 , dashed line box  54  is representative of a forwardly entrained vehicle, preferably in the nature of a wheeled agricultural fertilizer applicator. Such applicators are commonly towed by a tractor (not depicted within views) for introduction of nitrogen fertilizing NH 3  into the soil. Anhydrous ammonia within tank  62  is forwardly supplied via pressure hose  74  to such fertilizer applicator  54 . 
     In use of the instant inventive trailer hitch  1 , the release plate  16  may be initially slidably received within clevis space  5 , and cylinder  30  may be initially operated to downwardly telescope the distal end  27  of the bolt/piston shaft  26  through the second eye  12 , thence further downwardly through the first eye  17 , and finally through the third eye  15  of plate  14 . 
     Right and left safety chains  50  and  52  may be initially detached, allowing an operator to easily and conveniently carry the hitch  1  by grasping “D” loops  20  and  24  in his or her right and left hands. Thereafter, the hitch  1  may be lifted, and the vehicle mount pin  38  may be aligned with the rearward opening of receiver  56 . Thereafter, pin  38  may be slidably moved within receiver  56  until eyes  40  align with eyes  58 . Thereafter, a slide pin  60  may be extended laterally through such aligned eyes, securely attaching the hitch  1  to, for example, the fertilizer applicator  54 . 
     Thereafter, the fertilizer applicator  54  may be rollably moved and positioned to an orientation at which tang  46  overlies clevis ears  66  and  68  at the forward end of tongue  64 . Thereafter, the tongue  64  may be raised while the tang  46  is positioned between clevis ears  66  and  68  as indicated in  FIG. 3 . Thereafter, slide pin  46  may be extended downwardly through aligned eyes to fixedly and pivotally interconnect the anhydrous ammonia trailer  62  and the hitch  1 . 
     Thereafter, as indicated in  FIG. 1 , safety chains  50  and  52  which are anchored to the tongue  64  via attachment loop  72  may be respectively connected to the hitch  1  by threading through the eyes  18  and  22  which are formed by the “D” loop handles  20  and  24 . Referring further to  FIG. 3 , an anhydrous ammonia supply hose  74  extending from tank  62  may be operatively attached to the fertilizer applicator  54 . Thereafter, a pressurized forward flow of NH 3  may be commenced via turning of valve actuator  75 . 
     In the event the tank trailer  62  has a toppling or rollover accident, such trailer may roll laterally over the ground, and may break the connection of the tongue  64  at tang and clevis joint  46 , 66 , 68 . In that event, safety chains  50  and  52  may advantageously prevent the trailer  62  from traveling over the ground in a direction different from and independently from the forward trailer towing vehicles  54 . In the event that such trailer toppling accident also breaks hose  74 , causing a cloud of NH 3  gas to spread over the ground and toward the vehicle&#39;s operator, the operator may operate the tractor&#39;s hydraulic power supply system to introduce high pressure hydraulic fluid via hydraulic line  36  into hydraulic fluid space  35 . Such pressurized hydraulic fluid injection drives piston  29  upwardly and upwardly retracts the piston shaft/bolt  26 . The bolt retraction simultaneously causes the distal end  27  of the bolt  26  to successively upwardly withdraw from and clear eyes  15 ,  17 , and  12  to assume the plate releasing position depicted in  FIG. 4 . Such upward bolt retraction allows the release plate  16  to freely slide rearwardly out of the clevis&#39;s “U” space  5 . Upon such rear sliding release, both the release plate  16  and the forward attachments of the safety chains  50  and  52  fall harmlessly to the ground while the towing tractor and towed implement  54  are driven forwardly away from and out of the growing cloud of ammonia gas. 
     Each structure of  FIG. 7  which is identified by a reference numeral having a suffix “B” is configured substantially identically with similarly numbered structures appearing in  FIG. 1 . In the  FIG. 7  configuration, pin  78  is sized for receipt by a receiver hitch (not depicted in views) of the type commonly installed at the rear of a heavy duty pickup truck. Due to the common absence within such trucks of a hydraulic power system, the linear motion actuator component comprises an electric motor driven jack screw actuator  80  having an extendable and retractable bolt shaft  84 , and having a 12-volt electric power lead  82 . Such actuator  80  may be easily actuated via a truck cab mounted switch which communicates electrically with lead  82 . In the  FIG. 7  configuration, the tang  90  has a solid tang base mount  86  at the rearward edge of the release plate  16 B, and has a swivel joint  88  is interposed between the tang&#39;s eye  92  and the base  86 . The swivel joint  88  is protective in the event a trailer rollover accident which might otherwise apply extreme torque to base  86 , resulting in an upward deflection of the rear end of clevis ear/plate  4 B. Such plate deflection may undesirably bind the peripheral edges of the second eye  12 B against bolt  84 . The low power of the electric jack screw actuator  80  (in comparison with the power of  FIG. 1 &#39;s hydraulic cylinder  30 ) may be unable to upwardly move the bolt  84  while binding at eye  12 B occurs. The interposition of swivel joint  88  lessens the risk of such eye/bolt binding and lessens the risk of a release failure in the  FIG. 7  configuration. 
     While the principles of the invention have been made clear in the above illustrative embodiment, those skilled in the art may make modifications to the structure, arrangement, portions and components of the invention without departing from those principles. Accordingly, it is intended that the description and drawings be interpreted as illustrative and not in the limiting sense, and that the invention be given a scope commensurate with the appended claims.