Patent Publication Number: US-4543889-A

Title: Hatch cover seal assembly

Description:
SUMMARY OF THE INVENTION 
     This invention relates to a &#34;hatch cover sealing assembly&#34; for hopper cars or trucks. 
     The present covers are usually constructed from an aluminium or fiber glass with the seal or sealing gasket attached thereto by adhesive or expensive structural design. The problem with these prior covers resides in their placement and design. The seals in such prior covers are normally placed beneath and within the periphery and are therefore exposed to the hatch opening. Potential contaminents adhere to the underside of the cover in the area that is radially external of the seal. Also inherent in the prior structures is the fact the seal or gasket must be compressed and by repeated compression will take a permanent set distracting from its effectiveness. 
     It is an object of the present invention to overcome the noted deficiencies of the prior structures. The present invention co-operates with hatch openings that are formed to provide a peripheral ring curved outwardly and downwardly of the opening, which together with an exterior gasket retainer will make up a sealing holding means. The gasket is of a singular ring configuration and of a diameter slightly less than that determined by the holding means. The gasket can be forcefully stretched until it snaps into place within the holding means where it will remain without the need of adhesives or other structural restrainers. 
     The present invention provides a gasket seal that is completely exterior of the hatch opening. The seal co-operates with an outer depending lip provided by the cover so that the hatch opening is in effect sealed entirely outside of its perimeter. The gasket seal of this invention is located outwardly of the hatch opening and is not attached to the underside of the cover thus leaving that surface exposed for ease in cleaning. The gasket seal of the present invention is not compressed but merely deflected and disposed between the depending lip of the cover and the gasket holding means. 
     Another added feature of this invention resides in the need of only a single pressure release latch rather than full diameter brace locks as previously required. 
     Other objects of this invention will be made apparent from the subsequent general description. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     The invention will be best understood by reference to the accompanying drawings which illustrate the preferred mode of construction and arrangement of parts by which the stated objects of the invention are achieved, and in which: 
     FIG. 1 is a side elevational view of the hatch opening ring and cover in latched position; 
     FIG. 2 is a view similar to FIG. 1 but showing the cover in an open position; 
     FIG. 3 is a fragmentary detailed view of the gasket seal and latch cover in a locked position; and 
     FIG. 4 is a fragmentary detailed sectional view similar to FIG. 3 but with parts in an unlatched position. 
    
    
     GENERAL DESCRIPTION 
     Referring to the illustrations depicting the structure of this invention the hatch opening is defined by a raised collar 10, the exposed free edge of which is flared outwardly and downwardly to provide a hatch ring 11. 
     On the exterior wall surface of the collar 10, positioned below and in spaced relation to the ring 11 is a gasket retainer 12. This gasket retainer 12 includes an outwardly and downwardly projecting free edge 13, that cooperates with the hatch ring 11 to form therebetween a gasket retaining area 14. 
     A stretchable circular gasket 15 having a set diameter equal to or slightly less than that defined by the gasket receiving area 14 is adapted to have its inner edge 16 stretched and snapped over the hatch ring 11 and into the gasket receiving area 14 as shown. 
     A hatch cover 17 is provided, and by a hinge strap 18 is attached to a hinge pin 19 provided by a hinge bracket 20 attached to the outer wall of the collar 10 as illustrated in FIGS. 1 and 2. 
     The cover 17 provides a peripheral edge flange 21 which is angularly disposed out of the normal plane of the cover 17, and which terminates into a generally radially extending lip 22. 
     The arcuated angle of the edge 13 of the retainer 12 is greater than that of the retained gasket 15, such that in an unlocked condition the outer edge of the set position of the gasket 15 is spaced from the edge 13 and projects into the path of movement of the flange 21 provided by the cover 17. 
     As shown in FIG. 3 when the cover 17 is in its closed position as shown in FIG. 1 the lip 22 will have engaged the free end of the gasket seal 15 and deflected the same into contact with the depending free edge 13 of the gasket retainer 12. In this position the gasket seal 15 will have effectively sealed the peripheral edge of the cover 17 exteriorly of the hatch opening as defined by the collar 10. 
     It should be noted that the sealing of the cover 17 is outboard of the hatch opening as well as substantially below that of the plane of the hatch opening. Thus any and all contaminents are prevented from entering the hatch opening or from having access to the inner underside of the cover 17. 
     As the gasket 15 comprises a semi-flexible circular ring it can be readily replaced within the gasket retainer 12 when required. 
     To effectively releasably lock the cover 17 upon the collar 10 there is provided a pressure relief latch 23. 
     As illustrated in FIGS. 3 and 4 there is mounted on the exterior wall of the collar 10, at a point diametrically opposite to that of the hinged bracket 20, a latch bracket 24. This bracket 24 provides a pivotal mounting 25 for a latch pin 26. The latch pin 26 includes a radially extending threaded stud 27 which has mounted thereon an internally threaded sleeve 28. This sleeve 28 provides a bushing for a pivot pin 29. Mounted on the pivot pin 29 is a manually actuated latch lever 30. This latch lever 30 provides a bearing shoulder 31 which is adapted to have adjustable contact with a latch plate 32 mounted upon the cover 17. 
     As shown the latch plate 32 provides a tapered wall 33 which terminates into a split horizontal base 34, that in turn terminates into bifurcated retaining posts 35. 
     As shown in FIG. 3 when the latch lever 30 is in its latching position it will have pivoted about pin 29 so as to bring its bearing shoulder 31 into facial contact with the horizontal base 34 of the latch plate 32. In such positon the lip 22 of the cover 17 will have deflected the free end of the gasket 15 into sealing contact with free edge 13 of the gasket retainer 12. Thus the cover is latched in a sealed condition upon the hatch ring 10. 
     When the latch lever 30 is pivoted into a opening position the bearing shoulder 31 will first engage the tapered wall 33 of the latch plate 32 permitting partial breaking of the sealed closure allowing internal pressures to be safely released from within the hopper car. Further pivotal movement of the latch lever 30 will permit it and its associate parts to be disengaged from the cover 17 permitting it to be fully opened, as seen in FIG. 2. 
     To compensate for various thicknesses of gaskets as well as pivotal deflection of the cover 17 the sleeve 28 may be threaded upon the stud 27 in either direction so as to vary the displacement between the pivot pins 26 and 29. This adjustment will vary the point of contact between the peripheral flange 21 of the cover 17 with the exposed free edge of the gasket 15. 
     It should also be noted that the heretofore described pressure relief latch 23 has a cam movement between its bearing shoulder 31 and the tapered wall 33 and base 34 of the latch plate 32. This permits the securing of the cover 17 upon the collar 10 and permits a semi-unlocked position to relieve built up pressure within the hopper car. 
     While I have illustrated and described the preferred form of construction for carrying my invention into effect, this is capable of variation and modification without departing from the spirit of the invention. I, therefore, do not wish to be limited to the precise details of construction as set forth, but desire to avail myself of such variations and modifications as come within the scope of the appended claims.