Non-jamming bin lid system
FIELD OF THE INVENTION 
     The present invention relates to balanced lid type commercial trash bin and lid assemblies. 
     BACKGROUND OF THE INVENTION 
     Initially, reference is made to my prior U.S. Pat. Nos. Re. 29,494, and 3,994,415. The arrangement shown in U.S. Pat. No. 3,994,415 has proved to be particularly useful for certain applications. In the arrangement shown in this last-mentioned patent, the balanced lid is provided with rollers which ride on the upper rim of a commercial trash bin as the balanced lid is partially opened in the upright position. A pair of additional rollers extend inwardly from the rear corners of the lid and engage a curved track which is fixed to the upper rear sides of the commercial trash bin. As the lid is partially opened in the upright orientation, the rollers at the rear corners of the lid are guided downwardly in the two tracks and the supporting rollers near the center of gravity of the lid roll back along the upper surface of the trash bin until a stop is engaged. When the trash bin is inverted to empty it, the lid rotates about the pins in the upper end of the generally vertically extending track. Then, however, when the trash bin is shaken, to completely empty all waste or trash material from it, the lid is vibrated in the vertical plane in an irregular manner and occasionally one of the pins slides up the vertically extending track and jams or deforms either the lid or the track as a result of the uneven stresses which occur when one pin, but not the other, rides up in its track. 
     A principal object of the present invention is to avoid this damage which has occurred in balanced lid type trash bin systems utilizing roller and track guides. 
     SUMMARY OF THE INVENTION 
     In accordance with the present invention, a balanced lid type commercial trash bin and lid system is provided with a track in the lid instead of on the trash bin, and rollers on the bin instead of on the lid. Further, the track is oriented at a significant angle with respect to the vertical when the lid is in the wide open position when the bin is inverted for dumping, thereby preventing oscillation of the lid along the track and the resultant jamming which has plagued this type of tracked assembly. 
     A synergistic advantage is provided by the dual function performed by the lid mounted track. Initially, in the upright position it guides the rear of the lid; and then in the upside-down orientation it provides a constraining pivot point, impervious to vertical oscillations which have damaged assemblies of this type where the track was mounted on the bin. 
     Other objects, features, and advantages of the invention will become apparent from a consideration of the following detailed description and from the drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 shows the trash bin and balance lid assembly in accordance with the invention with the lid in the closed position; 
     FIG. 2 is a partial cross-sectional view taken along lines II--II of FIG. 1; 
     FIG. 3 is a partial cross-sectional view taken along lines III--III of FIG. 1; 
     FIG. 4 is a cross-sectional view through the center of the lid and commercial trash bin assembly showing the lid in the partially open condition for emptying trash into the bin; and 
     FIG. 5 shows the trash bin inverted with the lid wide open. 
    
    
     DETAILED DESCRIPTION 
     Referring more particularly to the drawings, FIG. 1 shows a commercial trash bin 12 provided with a lid 14, and pocket tubes 16 by which the commercial bin may be raised, and inverted, so that the trash in it may be dumped into a garbage truck. The bin and lid assembly of the present invention is of particular interest in that the lid may be partially opened with very little effort, because it is substantially balanced as it is opened when the bin 12 is in the upright orientation. On the other hand, when the entire bin and lid 12, 14 are inverted, as shown in FIG. 5, the lid swings wide open so that the emptying of the trash bin 12 is not impeded by the presence of the lid 14. 
     Now, returning to FIGS. 1, 2 and 3, it may be noted that FIGS. 2 and 3 are partial cross-sectional views taken along lines II--II and III--III of FIG. 1. When the lid is partially opened with the bin 12 in the upright orientation, the user grasps the handle 18 and raises the lid 14, which is supported in a very nearly balanced condition on the rollers 20 which ride on the upper rim 22 of the bin 12. To guide the rear of the lid 14 in its downward motion encompassing the rear of the bin 12, a pair of tracks are provided, one of which is located at each end on the inside rear of the sides of the lid. One such track is shown at 24, with the pin or roller 26 which is secured to the upper rear corner of the bin 12. A similar track and pin assembly is located at the opposite end of the lid and bin precisely aligned with the track 24 and pin 26 as shown in FIG. 1. Accordingly, when the handle 18 is raised the roller 20 rolls back along the track 22 and the recessed track 24 rides downwardly while encompassing the pin 26 which is fixed in position. The track 22 on the upper rim of the trash bin 12 is provided with an inclined surface 28 which is engaged by the roller 20 at about the same time that the pin 26 engages the upper end 30 of the track 24. Either or both of these stops holds the lid 14 in the partially open position as shown in FIG. 4 for the depositing of garbage into it. 
     When the trash bin 12 is to be emptied, a garbage truck inserts the tines of its forklift into the pocket tubes 16 and swings the trash bin 12 with its associated lid 14 up and over the cab so that the trash bin is emptied into the garbage truck in the upside-down orientation as shown in FIG. 5. When the bin is in this position above the garbage truck, the operator frequently shakes the bin giving it some vigorous vertical oscillations in the course of such shaking. With previous arrangements in which the fixed pins were secured to the lid and generally vertically extending tracks were located along the rear edge of the bin, one end or the other end of the lid would tend to slide up the track giving very intense pressure as the result of this camming action, with the result that the tracks, the pins or the lids would frequently be deformed and damaged. 
     In accordance with the present invention, with the track 24 being located on the lid, with the lid being pivoted by 90° from the initial orientation as shown in FIG. 1, vertical oscillation of the trash bin 12 will not cause significant movement of the lid 14, because the track 24 extends off to the rear at a significant angle, thus precluding any relative movement of the lid 14 as a result of vertical oscillation of bin 12. 
     In conclusion, it is to be understood that other mechanical arrangements may be employed in place of certain of those disclosed herein. More specifically, for example, other arrangements may be provided for supporting the lid 14 in a substantially balanced manner, and other arrangements may be provided for raising and inverting the lid and trash bin assembly. Accordingly, the present invention is only to be limited by the scope of the appended claims.