Abstract:
An anti-spin and drift device and installation method for railway plug type car doors that prevents unintentional rapid rotation of the center door operation handle caused by accidental movement of the door. The anti-spin device rapid rotation in both directions and replaces existing pinion gear assemblies and one-directional anti-spin assemblies that interlink the operational handle with the door operating mechanism that activates multiple crank rod assemblies for opening and closing the doors.

Description:
BACKGROUND OF THE INVENTION 
     1. Technical Field 
     This invention relates to rail car doors that are of the type that are pivoted into and out of closure opening and slide transversely of the rail car wall thereafter. 
     2. Description of Prior Art 
     Prior art devices of this type have been directed for use on railway plug doors that use pivotal crank rod assemblies that support the door and crank activation rods that extend to a central door operation handle assembly. Such operational mechanisms have a selector gear with an interconnected activation drive pinion gear. Activation crank rods extend from the selector gear for opening and closing the door. The pinion gear has an operational handle for manual input thereto. Prior art anti-spin drives take the place of a pinion gear and have a ratchet gear engaged by directional pawl. Such devices prevent rapid spinning of the operational handle in one direction if the door is accidentally moved by cargo or loaders. The anti-spin devices of this type can be seen in U.S. Pat. Nos. 3,557,731, 3,660,938 and 4,920,894. 
     In U.S. Pat. No. 3,555,731 a ratchet lock is disclosed that replaces a standard pinion gear for engagement of a door operational gear. During rotation of the device&#39;s drive shaft to open the door from the door opening, the pinion gear will move in a direction to engage and clamp a ratchet wheel between it and a flange fixed to the shaft with an engagement pawl on the ratchet wheel so as to allow the clamped ratchet wheel to rotate in direction with the pinion gear to open the door and prevent rotation of the wheel in opposite direction to close the door. 
     In U.S. Pat. No. 3,660,938 a brake type drive mechanism is disclosed for plug type rail car doors having a pinion gear on a rotatable input shaft that when the drive mechanism connected to the door crank moves at a rate faster than that of the pinion gear and attached handle the pinion gear will move longitudinally on the drive shaft engaging a ratchet wheel that prevents further movement. 
     In U.S. Pat. No. 4,920,894 a modular anti-spin unit for railway car doors is disclosed which is secured to the existing handle of the actuation shaft that prevents rapid shaft rotation in one direction by frictional engagement with a ratchet gear. 
     SUMMARY OF THE INVENTION 
     The present invention provides for method of retrofitting a railway car door with a dual action multi-directional safety mechanism by replacing a standard pinion gear or one-way anti-spin mechanism. The safety mechanism includes a pair of rotatable pinion gears that have extended engagement travel restriction lugs extending therefrom. The pinion gears are threadably positioned on a handle drive shaft with a ratchet gear assembly being rotatably positioned over the respective lugs between frictional rings and held in place by respective apertured pressure plates. Upon unintentional rapid rotation of the drive handle shaft, the friction ring wedgeably engages the ratchet gear stopping directional rotation of the pinion gear interconnected therewith. 
     A method for replacing an existing rail car door handle activation assembly including multiple steps of removing and modifying existing components and adding selected fittings required to adapt the dual action anti-spin, anti-drift safety mechanism to an existing rail car door assemblies. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side elevational view of a railroad car plug type door; 
     FIG. 2 is a side elevational view of a dual action anti-spin drift mechanism in assembled form; 
     FIG. 3 is an end view on lines  3 — 3  of FIG. 2 illustrating ratchet gear teeth direction; 
     FIG. 4 is an end view on line  4 — 4  of FIG. 2; 
     FIG. 5 is a cross-sectional view of the dual action anti-spin and drift mechanism; 
     FIG. 6 is an enlarged side elevational view of the handle drive and assembly shaft of the invention; 
     FIG. 7 is an enlarged side elevational view of a pinion gear; 
     FIG. 8 is an enlarged side elevational view of a retaining pressure plate as seen in FIG. 3; 
     FIG. 9 is an enlarged front elevational view of the door operating mechanism; 
     FIG. 10 is a partial sectional view of a portion of the rail door with a one-way ratchet lock installed therein; and 
     FIG. 11 is a partial cross-sectional view of a railway car door retrofitted with a dual action anti-spin and drift device. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to FIG. 1 of the drawings, a railroad car  10  can be seen having a sidewall  11  with a car door opening  12  therein. A plug door assembly  13  is positioned for sealing relation with the opening  12 . Door support rails  14  and  15  are positioned above and below the opening  12  for engagement with the door assembly  13 . A plug door  16  is supported by a pair of crank rod assemblies  17  and  18  and are secured to the door  16 . The upper and lower ends of the crank rods each have lateral extending arm cranks  19 A and  19 B,  20 A and  20 B which are pivotally engaged by respective roller and wheel assemblies  21 A and  21 B,  22 A and  22 B in the respective rails  14  and  15  as will be well understood by those skilled in the art. 
     A door operating assembly  23  is secured to the door  16  having pairs of actuation rods  24  and  25 . The rods  24  extend to a plurality of lock bolt members  25 A positioned around the perimeter edge of the door  16 . The corresponding rods  25  are interengaged to the crank rods  17  and  18  for rotational movement thereof for the opening and closing the door as will be described in greater detail hereinafter. 
     The actuation rod pairs  24  and  25  are in communication with a selector gear  26 , best seen in FIG. 9 of the drawings. The vertical oriented activation rods  24  are pivotally connected to respective arm cranks  27  which are received within recesses  28  formed in the selector gear  26 . Correspondingly, the horizontally oriented activation rods  25  are pivotally secured to the selector gear  26  by respective pivot points  29  and  30 . 
     It will be apparent that upon clockwise rotation of the selector gear  26  as indicated by the rotational arrow A, it will accordingly retract the activation rods  24 A and  24 B and the activation rods  25  releasing the lock bolt mechanisms  25 A and rotating the crank rods  17  and  18  on their longitudinal axis respectively, unsealing the door  16  and pivoting it outwardly from the opening  12 . 
     The selector gear  26  is driven by the rotation of a door handle  31  and attached pinion gear  32  illustrated in FIG. 9 of the drawings. A safety anti-spin device  33  illustrated in FIG. 3 of the drawings replaces the existing pinion gear  32  providing dual action anti-spin and drift features to the operation assembly as indicated by the selection gear  26 . 
     Referring now to FIGS. 2-8 of the drawings, the safety anti-spin device  33  can be seen having a pair of pinion gear assemblies  34  and  35  threadably positioned on a drive shaft  36  at  36 A. The handle  31  is registerable on a squared engagement portion  37  of the shaft  36  and retained by a nut  67  shown in broken lines threadably positioned on one end of the drive shaft  36  at  36 B. 
     Referring now to FIGS. 5 and 7 of the drawings, it will be seen that the pinion gear assemblies  34  and  35  each respectively have an annular flange  38 A and  38 B defining an annular tapered portion fittings  39 A and  39 B extending therefrom. A pair of oppositely disposed arcuate lugs  40 A and  40 B extend from the respective tapered portions  39 A and  39 B. The respective flanges  38 A and  38 B have smooth engagement surfaces  39 C and  39 D that receive first respective first frictional washers  41 A and  41 B as best seen in FIG. 5 of the drawings. The second frictional washers  41 C and  41 D are positioned over the lugs  40 A and  40 B abutting the first washer  41 A and  41 B. Respective ratchet wheels  42 A and  42 B having oppositely disposed recessed portions  43  and  44  about a central opening therein are rotatably positioned over the respective second friction washers  41 C and  41 D bearing thereon. The respective ratchet wheels  42 A and  42 B are positioned to be directionally reversed to one another as will be discussed in greater detail hereinafter. A third frictional washer pair  46 A and  46 B identical to the first frictional washer pair is engaged within the respective oppositely disposed recess portion  44 . 
     A pair of pressure engagement plates  46  and  47 , best seen in FIGS. 3,  4 ,  5  and  8  of the drawings have vertically offset apertured center portions  48  and a pair of oppositely disposed arcuate slots  49  and  50  therein. The plate  46  is retained in position on the drive shaft  36  by welding at  51  to a retaining flange  52  on the drive shaft  36  with the lugs  40 A and  40 B extending through respective openings at  49  and  50  therein. It will be evident from the above description when viewing FIG. 5 of the drawings, that the remaining pinion gear assembly is identical with the exception of the pressure plate  47  that has a central opening of a reduced dimension to registerably engage the area of reduced drive shaft dimension at  53  and is welded to the drive shaft  36  at  51 A. A flat retaining washer  54  is positioned on the drive shaft  36  portion  53  and is secured to the pressure plate  47  by welding at  51 B. 
     Referring now to FIGS. 5 and 11 of the drawings, a ratchet engagement pawl assembly  53  can be seen having a first ratchet pawl  54  on a support shaft  55  arranged for directional engagement with the ratchet wheel  42 A providing counter clockwise rotation as viewed from FIG. 3 of the drawings. A second ratchet pawl  56  is positioned on an extension shaft element  57  of the invention as will be discussed in greater detail hereinafter and is engaged on the ratchet wheel  42 B which will prevent rotation in a clockwise direction. 
     In operation, as the rail car door  16  is opened the handle  31  is rotated in a counter clockwise direction. The drive shaft  36  is in turn rotated causing the pinion gear assembly  33  to move marginally engaging the assembly&#39;s first friction washer  41 B on the ratchet wheel  42 B and correspondingly to engage the pressure plate  47  via the second frictional washer  41 D. The ratchet pawl  56  prevents clockwise rotation of the ratchet wheel  42 B when engaged as noted. The lugs  40 A and  40 B limit travel of a pinion gear portion  58  by their respective engagement within the travel slots  49  and  50  of the pressure plate  46  as hereinbefore described. 
     It will be evident that as the counter clockwise rotation continues, the pinion gear portion  58  will drive the selection gear  26  clockwise as seen in FIG. 9 releasing the door locks  25 A and rotating the crank shaft rods  17  and  18  moving the door  16  outwardly from the door opening  12 . Should the door be forced outwardly by the contents of the rail car or sudden unintentional rotation of the selection gear  26  occur, the gear will in turn rotate the inner connected pinion gear portion  58  and correspondingly handle  31  over spinning causing injury to the operator (not shown). Rotation of the pinion gear portion  58  in a counter clockwise direction at a rate greater than the rate at which it is being rotated by the handle  31 . This will cause the pinion gear portion  58  to rotate marginally on the drive shaft  36  to engage the ratchet wheel  42 A thus preventing further rotation of the handle  31  by the action of the pawl  54 . Once the force on the door is released, the handle  31  can again be rotated in a counter clockwise direction to continue opening the door  16 . 
     Once the door  16  is fully opened and closing of the door  16  is desired then clockwise rotation of the handle  31  will cause the pinion gear assembly  35  to move on the drive shaft  36  and engage the friction washer  41 B of the ratchet wheel  42 B locking same to the pinion gear portion  59  and rotate therewith. The pawl  56  prevents counter clockwise rotation in the same sequence of events as described above with the pinion gear assembly  34 . 
     It is important to note that by the use of independent pinion gear portions  58  and  59  with both inner engaging the selection gear  26 , that the incremental gear play therebetween allows for lock release of the non-engaged pinion gear assembly to its respective ratchet wheel under reverse rotation sequence in regards to one another. This is a critical improvement over monolithic pinion gear assemblies of prior art in which unlocking of the opposite friction engagement assembly is difficult. 
     Correspondingly, if the door  16  is forced closed by an outside force, the selection gear  26  will rotate the pinion gear portion  59  at a speed greater than normal closing rotation and correspondingly cause the pinion gear assembly  35  to rotate marginally on the drive shaft  36  engaging the ratchet wheel  42 B preventing further rotation as hereinbefore described by the engagement action of the pawl  56 . 
     Referring now to FIGS. 10 and 11 of the drawings, a method of replacing an existing one-directional anti-spin anti-drift device  60  can be seen and described hereinafter. The rail door  16  has a rear support wall  62  and spaced front cover plate  63 . The existing one-directional anti-spin device  60  is positioned within having the selection gear  26  engaged on a pinion gear  64 . Existing pawl assembly  54 A with pawl  54  directionally engages a ratchet fitting  65 . An activation handle  66  is secured to a drive shaft  67  by a retainer nut  67 A as best seen in FIG. 10 of the drawings. 
     Referring now to FIG. 11 of the drawings, the dual action anti-spin, anti-drift device  33  of the invention is inserted in the following sequential steps. 
     The original door handle  66  is removed via a retainer nut  67 A. The front cover plate  63  (also illustrated in FIG. 1 for reference) is removed along with a snap ring  68 . 
     Removal and discarding the original anti-sp in, anti-drift device  60 . 
     Remove and save the original ratchet pawl  54  and discard associated spacer  54 A. 
     Install the ratchet anti-spin anti-drift assembly  33  of the invention by pulling the selection gear  26  forward to provide clearance and then backwards for engagement with the multiple pinion gear portions  58  and  59  of the anti-spin assembly  33  as it is positioned in the door  16  as seen in FIG. 11 of the drawings. 
     Re-install the original ratchet pawl  54 . 
     Apply a pawl washer  69  on top of the ratchet pawl  54  then threadably secure the ratchet pawl stud extension  57  and confirm ratchet pawl  54  and washer  69  are free turning thereon. 
     Position a second ratchet pawl  56  on the stud extension  57 . 
     Modify the original cover plate  63  by cutting a clearance opening at  70  using a guide template (not shown) but position illustrated by broken lines T in FIG. 9 of the drawing. 
     Re-install modified cover plate  63 A, positioning and installing a stainless steel bushing  72  on the drive shaft  36 . 
     Positioning a secondary cover plate  73  having a handle aperture at  74  and mounting aperture at  75  over the axis opening at  70 . 
     Registering respective drive shaft  36  and pawl extension  57 . Temporarily securing same with lock nut  76 . 
     Ideally, the door handle  66  is repositioned on the drive shaft  36  and secured by the original lock nut  67 A. In most applications, however, due to the overall rail car width restriction, a new door handle  77  illustrated in FIG. 11 of the drawings in solid lines must be used which has a less longitudinal offset as indicated by comparison with original handle  66  shown in broken lines with a dimensional difference indication therebetween at D. 
     Once the proper door operation has been confirmed, the cover plate  73  is tack welded into place, as illustrated. 
     As set forth in the method steps above, the dual action anti-spin anti-drift device  33  of the invention will prevent unintentional rapid handle rotation in either direction by braking engagement with the respective pinion gear fittings  34  and  35  and respective interconnected pawls  54  and  56  of rotational limitation on the engagement for respective ratchet wheels  42 A and  42 B. 
     Accordingly, directional non-restrictive rotation of the ratchet wheels  42 A and  42 B is possible by reverse ratchet direction orientation with respect to teeth orientation thereon and pinion gear independent assemblies directed therebetween. 
     It will therefore be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit of the invention. Therefore I claim: