Trolley with tractor drive for use in curved enclosed tracks and system including the same

Abstract

An enclosed track system comprising an enclosed track having at least one curve and a trolley for negotiating the curve. The trolley includes an externally located drive section and a rolling section having first and second roller portions located within the track. The first roller portion includes rollers for rolling on flange portions of the track. The second roller portion includes a driven wheel and a pair of support rollers. The driven wheel rolls on an inner surface of the top of the track. The pair of support rollers roll on flange portions of the track and are mounting on respective rods for pivoting action about vertical axes. The drive section includes a motor, a drive sprocket and associated chain for positively driving the driven wheel. The drive section also includes an articulated joint coupling the first and second roller portions together.

1 . A trolley for use with an enclosed track having at least one curved portion, the enclosed track being an elongated hollow member having a top wall portion, a pair of side wall portions and a pair of flanged portions, the flanged portions being spaced from each other to define a slot there between extending longitudinally along the track, said trolley comprising a rolling section and a drive section, said rolling section comprising first and second roller portions, said first roller portion being located within the track and comprising at least one support roller arranged to roll on at least one of the flange portions of the track, said second roller portion comprising a driven wheel and a pair of support rollers, said drive section being located outside of the track and including a driving sprocket and an associated driving loop, said driving sprocket being arranged for positively engaging said driving loop, said driving loop being arranged for positively engaging said driven wheel to cause said driven wheel to rotate about a horizontal axis, said pair of support rollers comprising an upstream support roller and a downstream support roller, said upstream support roller being located adjacent one side of said drive wheel and mounted on said drive section for pivoting action about an upstream vertical axis, said downstream support roller being located adjacent a diametrically opposed side of said driven wheel and mounted on said drive section for pivoting action about a downstream vertical axis, whereupon said upstream and downstream support rollers are enabled to roll along at least one of the flange portions of the track while said driven wheel rolls along the top wall portion of the track in the center thereof. 
   
   
       2 . The trolley of  claim 1  wherein said driving loop comprises a chain. 
   
   
       3 . The trolley of  claim 1  additionally comprising at least one spring for biasing said driven wheel into engagement with the top wall of the track. 
   
   
       4 . The trolley of  claim 1  additionally comprising a pair of guide rollers mounted on respective vertically extending rods connected to said second roller portion, each of said guide rollers being and located within the slot in the track, with said guide rollers being positioned immediately fore and aft of the position of said driven wheel. 
   
   
       5 . The trolley of  claim 4  wherein said first roller portion is coupled to said second roller portion by an articulated joint, said articulated joint comprising an elongated member, said elongated member having a first end portion and a second end portion, said first end portion being pivotably coupled to said first roller portion at a first vertically extending axis, said second end portion being pivotably coupled to said second roller portion at a second vertically extending axis, said second vertically extending axis being located approximately midway between said vertically extending rods of said guide rollers. 
   
   
       6 . The trolley of  claim 5  wherein said articulated joint additionally comprises a tow-arm swing plate, and wherein said elongated member is comprises a yoke like member having a pair of arms, each of which includes a respective end fixedly secured to said tow-arm swing plate, said tow-arm swing plate being mounted for pivoting about said second vertically extending axis. 
   
   
       7 . A trolley for use with an enclosed track having at least one curved portion, the enclosed track being an elongated hollow member having a top wall portion, a pair of side wall portions and a pair of flanged portions, the flanged portions being spaced from each other to define a slot therebetween extending longitudinally along the track, said trolley comprising a rolling section and a drive section, said rolling section comprising first and second roller portions, said first roller portion being located within the track and comprising at least one support roller arranged to roll on at least one of the flange portions of the track, said second roller portion comprising a driven wheel and a pair of support rollers, said first and second roller portions being coupled together by an articulating joint, said second roller portion comprising a pair of guide rollers mounted on respective vertically extending rods, each of said guide rollers being and located within said slot, with said guide rollers being positioned immediately fore and aft of the position of said driven wheel, said drive section being located outside of the track said driving section being arranged for driving said driven wheel to cause said driven wheel to rotate about a horizontal axis, said pair of support rollers comprising an upstream support roller and a downstream support roller, said upstream support roller being located adjacent one side of said drive wheel and mounted on said drive section for pivoting action about an upstream vertical axis, said downstream support roller being located adjacent a diametrically opposed side of said driven wheel and mounted on said drive section for pivoting action about a downstream vertical axis, whereupon said upstream and downstream support rollers are enabled to roll along at least one of the flange portions of the track while said driven wheel rolls along the top wall portion of the track in the center thereof, said articulated joint comprising an elongated member, said elongated member having a first end portion and a second end portion, said first end portion being pivotably coupled to said first roller portion at a first vertically extending axis, said second end portion being pivotably coupled to said second roller portion at a second vertically extending axis, said second vertically extending axis being located approximately midway between said vertically extending rods of said guide rollers. 
   
   
       8 . The trolley of  claim 7  wherein said articulated joint additionally comprises a tow-arm swing plate, and wherein said elongated member is comprises a yoke like member having a pair of arms, each of which includes a respective end fixedly secured to said tow-arm swing plate, said tow-arm swing plate being mounted for pivoting about said second vertically extending axis.