Monorail vehicle apparatus with trucks designed to accommodate movement along curved rail sections

Abstract

The present invention teaches a monorail vehicle apparatus and method for controlling roll attitude, lateral location, and loading of a monorail vehicle traveling on a non-featured rail exhibiting substantial profile variation by the placement of the vehicle's center of gravity and without the use of additional mechanisms such as springs or suspensions. The design is especially well adapted for travelling along curves by using at least two trucks connected by a linkage mechanism.

We claim: 
     
         1 . A monorail vehicle apparatus wherein roll attitude and loading are constrained by the placement of a center of gravity, said apparatus comprising:
 a) a non-featured rail extending along a rail centerline;   b) a monorail vehicle having a bogie for engaging said non-featured rail such that said center of gravity of said monorail vehicle has a lateral offset r 1  from said rail centerline thereby creating a roll moment N r  about said rail centerline, said bogie comprising:
 1) a drive mechanism for displacing said monorail vehicle along said non-featured rail; 
 2) at least two trucks connected by a connector mechanism and each of said at least two trucks comprising:
 i) a first assembly for engaging said non-featured rail on a first rail surface; 
 ii) a second assembly for engaging said non-featured rail on a second rail surface, said first rail surface and said second rail surface being selected to produce a pair of surface normal reaction forces resulting in roll attitude and loading of said monorail vehicle being controlled by the placement of said center of gravity; and 
 
   said center of gravity further having a predetermined vertical offset r 2  from said rail centerline.   
     
     
         2 . The monorail vehicle apparatus of  claim 1 , wherein said connector mechanism comprises a rigid plate. 
     
     
         3 . The monorail vehicle apparatus of  claim 2 , wherein said rigid plate is comprised of metal. 
     
     
         4 . The monorail vehicle apparatus of  claim 1 , wherein each of said at least two trucks is connected to said connector mechanism by a linkage mechanism. 
     
     
         5 . The monorail vehicle apparatus of  claim 4 , wherein said linkage mechanism comprises a pivot portion that allows for rotation by up to a predetermined number of degrees, of said truck around axis that is largely orthogonal to said rail centerline. 
     
     
         6 . The monorail vehicle apparatus of  claim 4 , wherein said linkage mechanism further comprises a pivot portion that allows for rotation by up to a predetermined number of degrees, of said truck around axis that is largely parallel to said rail centerline. 
     
     
         7 . The monorail vehicle apparatus of  claim 4 , wherein said linkage mechanism is selected from the group consisting of ball bearing joints, ball and socket joints, flexible metal, flexible plastic, rubber, springs, dampers, compliant linkages, helical couplings, universal joints, gimbals and magnetic couplings. 
     
     
         8 . The monorail vehicle apparatus of  claim 7 , wherein said non-featured rail has at least one curve. 
     
     
         9 . The monorail vehicle apparatus of  claim 8 , wherein said curve has a curvature determined by its minimum radius, and torsional stiffness, minimum lateral bending stiffness, minimum vertical bending stiffness and maximum material stress of said non-featured rail. 
     
     
         10 . The monorail vehicle apparatus of  claim 9  wherein said curvature is further determined by said predetermined number of degrees of rotation of said truck allowed by said linkage mechanism around an axis largely orthogonal to said rail centerline. 
     
     
         11 . The monorail vehicle apparatus of  claim 9  wherein said curvature is further determined by said predetermined number of degrees of rotation of said truck allowed by said linkage mechanism around an axis largely parallel to said rail centerline. 
     
     
         12 . A method for constraining roll attitude and loading of a monorail vehicle traveling along a non-featured rail extending along a rail centerline by the placement of a center of gravity, said method comprising the steps of:
 a) providing said monorail vehicle with a bogie;   b) engaging said bogie with said non-featured rail such that a center of gravity of said monorail vehicle has a lateral offset r 1  from said rail centerline thereby creating a roll moment N r  about said rail centerline;   c) moving said monorail vehicle along said non-featured rail with a drive mechanism;   d) providing said bogie with at least two trucks;   e) providing a connector mechanism to connect said at least two trucks;   f) providing each of said at least two trucks with a first assembly for engaging said non-featured rail on a first rail surface;   g) providing each of said at least two trucks with a second assembly for engaging said non-featured rail on a second rail surface, whereby said first rail surface and said second rail surface are selected to produce a pair of surface normal reaction forces for controlling said roll attitude and loading by the placement of said center of gravity;   h) locating said center of gravity at a vertical offset r 2  from said rail centerline.   
     
     
         13 . The method of  claim 12 , wherein said connector mechanism is provided with a rigid construction. 
     
     
         14 . The method of  claim 13 , further comprising the step of deploying at least one metallic component in said rigid construction. 
     
     
         15 . The method of  claim 12 , further comprising the steps of:
 a) providing a connector mechanism; and   b) providing a set of linkage mechanisms; and   b) attaching each of said at least two trucks to one said linkage mechanism; and   c) further attaching each said linkage mechanism to said connector mechanism.   
     
     
         16 . The method of  claim 15 , wherein said linkage mechanism allows for rotation of each of said at least two trucks by up to a predetermined number of degrees, around axes that are largely orthogonal to said rail centerline. 
     
     
         17 . The method of  claim 15 , wherein said linkage mechanism further allows for rotation of said at least two trucks by up to a predetermined number of degrees, around axes that are largely parallel to said rail centerline. 
     
     
         18 . The method of  claim 12 , wherein said non-featured rail is provided with at least one curve, said at least one curve being determined by its minimum radius, and minimum torsional stiffness, minimum lateral bending stiffness, minimum vertical bending stiffness and maximum material stress of said non-featured rail, and said predetermined number of degrees of rotation of said trucks allowed by said linkage mechanism around axes largely orthogonal to said rail centerline. 
     
     
         19 . The method of  claim 12 , wherein said non-featured rail is provided with at least one curve, said at least one curve being determined by its minimum radius, and minimum torsional stiffness, minimum lateral bending stiffness, minimum vertical bending stiffness and maximum material stress of said non-featured rail, and said predetermined number of degrees of rotation of said trucks allowed by said linkage mechanism around axes largely parallel to said rail centerline.