Patent Document

CROSS REFERENCE TO RELATED APPLICATION 
     The instant application is a continuation-in-part of patent application Ser. No. 11/148,997, filed Jun. 10, 2005, entitled, “Railway Car Door Operator Assembly” (now abandoned). 
    
    
     BACKGROUND OF THE INVENTION 
     This invention relates to an improved railway car door operator assembly which is mountable on a self-propelled vehicle for selectively opening and closing railway car doors. 
     A common problem with railway car doors is that a substantial amount of force is required either to open the door or to close the door. The utilization of a vehicle to open or to close a door is well recognized. Three prior art patents show devices attached to a forklift truck for opening or closing a railway car door. Those prior art patents are: U.S. Pat. No. 4,149,644, entitled, “Fork Lift Truck Attachment” issued Apr. 17, 1979, to Richard C. Fuller; U.S. Pat. No. 4,160,509, entitled, “Freight Car Door Opener” issued Jul. 10, 1979, to Ralph V. Switzer; and U.S. Pat. No. 4,290,730, entitled, “Attachment For Fork Lift” issued Sep. 22, 1981, to James A. Weaver. The devices shown in the three prior art patents are effective in a situation wherein the truck may move in a straight line the length of the distance required for opening or closing the door. However, there are situations wherein the truck is prohibited from moving in a straight line. For instance, if a loading dock is enclosed, that is, it is under a roof with walls and the walls have openings just large enough to align with the opening of a box car. In those instances, the known freight car door openers may not be used effectively due to the space limitations interiorally of the loading dock. 
     It is an object of the present invention to provide an improved railway car door operator assembly which is mountable on a self-propelled vehicle, such as, a forklift truck either to open or to close a freight car door in a minimum of space. Other objects and uses of the present invention will become readily apparent to those skilled in the art upon perusal of the following specification in light of the accompanying drawings. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention is an improved railway car door operator assembly for mounting on a self-propelled vehicle to open or to close selectively railway car doors. The vehicle is supported on and operable as a substantially horizontal support surface. The door operator assembly includes a base which is mountable on a self-propelled vehicle. An elongated operating arm having a pair of opposed arm ends has one of the arm ends movably connected to the base by an articulated joint. The articulated joint limits the arm to movement substantially parallel to the support surface. A releasable restraint is mounted on the other of the opposed arm ends. The restraint is releasably connectable to a railway car door for secure attachment of the operator assembly to the railway car door, so that movement of the vehicle moves the door. 
    
    
     
       BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWING 
         FIG. 1  is a perspective view of the railway car door operator assembly embodying the present invention shown mounted on a forklift truck; 
         FIG. 2  is a perspective view of a portion of the car door operator assembly releasably locked to a mast of the forklift truck; 
         FIG. 3  is a cross sectional view taken on Line  3 - 3  of  FIG. 2 ; 
         FIG. 4  is a cross sectional view taken on Line  4 - 4  of  FIG. 1 ; 
         FIG. 5  is a perspective view of the railway car door operator assembly connected to a railway car door through an opening in an enclosed loading dock; 
         FIG. 6  is a schematic view showing an initial position of the railway car door operator assembly mounted on a forklift truck and connected to a railway car door through an opening in an enclosed loading dock; 
         FIG. 7  is a schematic view like  FIG. 6 , but showing the position of the railway car door, the operator assembly and the forklift truck during the movement of the forklift truck in the initial step of opening the railway car door; 
         FIG. 8  is a schematic view similar to  FIG. 6 , but showing another position after the position shown in  FIG. 7  in the steps of opening the railway car door; 
         FIG. 9  is a schematic view similar to  FIG. 6 , but showing the position of the railway car door operator assembly and forklift truck in one step after that shown in  FIG. 8 ; and 
         FIG. 10  is a schematic view similar to  FIG. 6  showing the final position of the railway car door in a fully opened position and the position of the operator assembly and forklift truck when the door is fully opened. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the drawings, and in particular  FIG. 1 , a railway car door operator assembly which is a specific embodiment of the instant invention is shown therein and is generally indicated by numeral  20 . Operator assembly  20  is shown mounted on a self-propelled vehicle and in this case, a conventional and well known forklift truck generally indicated by the numeral  22 . The truck is conventionally supported on a conventional horizontal support surface, that is, floor  23 , as may be seen in  FIG. 5 . 
     Forklift truck  22  includes a conventional body  24  having a pair of front wheels  26  and a pair of turnable rear wheels  28 . Wheels  26  and  28  operably engage floor  23 , as is conventional. A mast  30  is mounted on the front portion of the body with a pair of forwardly extended conventional prongs  32  and  34  mounted on the mast. The prongs  32  and  34  shown herein are conventionally flat forwardly extending prongs and are shown solely for the purpose of illustration. It is to be understood that other types of devices for holding material may be used rather than the prongs shown herein. For instance, curved prongs may be used such as those which are often used in paper mills. The operation of forklift truck  22  is conventional and is well known. 
     Railway car door operator assembly  20  generally includes a base  36  connected to a longitudinal arm  38  through an articulated joint  40  movably connecting the longitudinal arm with the base. A restraint  42  is connected to one end of longitudinal arm  38  through a swivel  44 , as may be seen in  FIG. 1 . The restraint  42  may be a hook, shackle, or other securing device which may be readily and releasably secured to a railway car door. 
     Base  36  has a mounting end  46  positioned adjacent to the forklift truck when operationally mounted on the truck. A forward end  48  of the base is opposed to the mounting end. The base includes a pair of spaced angle beams  50  and  52 . Upper cross braces  54 ,  56  and  58  are welded to the upper portion of angle beams  50  and  52 . Three lower cross braces  60 ,  62  and  64  are welded to the lower portion of beams  50  and  52  to define a prong receptacle adjacent to mounting end  46 . A pair of support plates  66  and  68  is welded to the beams  50  and  52  at forward end  48 . A head plate  69  is welded to support plates  66  and  68  at the forward end, as may be seen in  FIG. 4 . 
     Longitudinal arm  38  is a box construction having a hollow interior to provide a light weight to strength construction relative to a sold construction. Arm  38  has a pair of opposed arm ends  70  and  72  and has a longitudinal axis which extends between the two arm ends. Support arm end  70  is connected to the base by articulated joint  40 . The opposite end of the longitudinal arm is connector end  72  which is connected to restraint  42 . As may be best seen in  FIG. 4 , articulated joint  40  includes a threaded pivot pin  74  which has a head  76  formed integral therewith. A washer  78  is positioned between head  76  and longitudinal arm  38 . An upper inner nut  80  is mounted on the pivot pin in engagement with plate  66 . A lower inner nut  82  is mounted on the pivot pin in engagement with plate  66 . The pivot pin is the axis for pivoting of arm  38  and is perpendicular to the longitudinal axis of arm  38  and to the base. Thus, articulated joint  40  allows the longitudinal arm  38  to pivot about the base on an axis of pivoting which is perpendicular to the longitudinal axis of the longitudinal arm and to the base, so that arm  38  is limited in movement relative to the base substantially parallel to floor  23 . 
     Swivel  44  includes an eyebolt  84  mounted in connector end  72  of the longitudinal arm. A link  86  is mounted on the eyebolt. A shackle link  88  is also mounted on link  86 . The restraint  42  includes a hook  90  which has a shackle rod  92  pivotedly connected at one end of the hook. The other end of rod  92  is pivotal in link  88 . A dog  94  is pivotedly connected to the hook for securing the hook when the hook is positioned in place. 
     An angle iron mounting bracket  96  is welded to beams  50  and  52  at the mounting end of the base. The mounting bracket has a pair of lock studs  98  and  100  mounted therein. A lock  102  is connected to the base and engages mast  30  of the forklift truck to secure releasably the base to forklift truck  22 . Lock  102  includes a chain  104  which has a link  106  secured to locking stud  98 . The lock includes a link  108  secured to locking stud  100 . A hook  110  is connected to link  108  and is engagable with a selected link of chain  104  so that the base may be secured to mast  30 . 
     The utilization of the subject railway car door operator assembly is described below for the purpose of illustration of how the subject assembly may be used but the illustration is not intended to limit the use of the instant assembly. Referring now to  FIG. 5 , a portion of conventional enclosed loading dock is shown therein having a floor  23  with a wall  114  on the floor. The wall has an opening  116  therein. Opening  116  may be selectively closed by a door which is not shown herein. A railway car  118  is spotted adjacent to the dock with a door  120  of the car aligned with opening  116 . 
     Railway car door operator  20  is mounted on forklift truck  22  by moving truck  22  forward to insert prongs  32  and  34  into base  36  and continue moving truck  22  toward the base until mounting end  46  abuts mast  30 . Chain  104 , which has links  106  fixed to mounting bracket  96 , is wrapped around mast  30  of the forklift truck and hook  110  is secured in a link of chain  104  to secure the operator assembly to the forklift truck. The forklift truck with the operator assembly is moved to a position adjacent to a railway car door  120 , which is to be opened. Restraint  42  is positioned in a conventional pocket of the door wherein hook  90  is positioned in the pocket and dog  94  locks the restraint to door  120 . 
     Once the restraint is secured to door  120 , forklift truck  22  is operated to pull open the door in the direction indicated by arrow  121 . Several steps in moving the forklift truck with the operator assembly to open door  120  are shown in  FIGS. 6-10 . The initial position of the operator assembly and forklift truck relative to door  120  is shown in  FIG. 6 . Forklift truck  22  is then moved in the direction shown by arrow  123  to swing base  36  of the operator assembly in a counterclockwise direction as indicated by arrow  125  and swing the arm parallel to the floor. The forklift truck is moved away from the door. This movement applies a tensile force to the longitudinal arm to move door  120  initially. The continuous swinging of the base as shown by arrow  127  and movement of the forklift truck as shown by arrow  129  positions the forklift truck and arm to the attitude shown in  FIG. 7  wherein the door is partially opened. The forklift truck is then moved further away from the door and pivoted as identified by arrow  131  and the base is swung in a clockwise position as identified by arrow  133  so that the position of the forklift truck with the operator assembly and door is that shown in  FIG. 8 . The base is pivoted in a counterclockwise position as identified by arrow  135  and the forklift truck is moved toward the railway car as shown by arrow  137  to the attitude shown in  FIG. 9  to apply a compression force to the longitudinal arm. The arm is moved to the attitude shown in  FIG. 10 , so that the railway car door is completely opened. 
     The railway car door may be closed by attaching the restraint to the door with the forklift truck and operator assembly in the attitude shown in  FIG. 10 . Base  36  is pivoted in a clockwise direction as identified by arrow  139  and the forklift truck is moved in the direction shown by arrow  141  and door  120  is moved to close the opening in the box car indicated by double arrow  143  showing movement of the door in either direction. The steps used in opening the door are simply reversed in order to close the railway car door. 
     From the foregoing description in light of  FIGS. 6-10 , it may be seen how the forklift truck is kept in a confined area aligned with the opening in the loading dock. It is not necessary to move the forklift truck along the loading dock to open the door, but rather the forklift truck may be readily utilized to open and close the door in a relatively narrow space. 
     Although a specific construction of the herein disclosed invention has been described in detail, it is readily apparent that those skilled in the art may make various modifications and changes without departing from the spirit and scope of the present invention. It is expressly understood that the present invention is limited only by the appended claims.

Technology Category: b