Low floor vehicle ramp assembly

Abstract

A ramp assembly ( 20 ) for mounting in a low floor bus ( 22 ) or other vehicle. The ramp assembly ( 20 ) includes a rectangular enclosure ( 24 ) that fits underneath the chassis of the low floor bus ( 22 ). The ramp assembly ( 20 ) includes a reciprocating mechanism ( 26 ) for moving a ramp platform ( 28 ) between a fully deployed position and a fully stowed position. During this movement, the reciprocating mechanism ( 26 ) raises the trailing end of the ramp platform ( 28 ) in one translational movement with the extension of the ramp platform, such that the trailing end of the ramp platform, when deployed, is raised to the floor level of the low floor bus ( 22 ).

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:  
     
         1 . A ramp assembly comprising: 
 a frame;    a ramp platform mounted in the frame defining trailing and forward ends and extendable and retractable along a length of the frame between stowed and deployed positions, the ramp platform being stowed substantially along a plane, and being arranged when deployed such that the forward end extends down toward the ground;    a first locking mechanism that locks the ramp platform into a fully deployed position;    a second locking mechanism that locks the ramp platform into a fully stowed position; and    a single manual release mechanism, actuation of which releases the first locking mechanism when the ramp assembly is in the fully deployed position and which releases the second locking mechanism when the ramp platform is in the fully stowed position.    
     
     
         2 . The ramp assembly of    claim 1   , wherein the first locking mechanism comprises a first latch arm operatively associated with the ramp platform to extend and retract with the ramp platform and a first latch plate attached to the frame that is engaged by the first latch arm when the ramp platform is in the fully deployed position.  
     
     
         3 . The ramp assembly of    claim 1   , wherein the first locking mechanism comprises a second latch arm operatively associated with the ramp platform to extend and retract with the ramp platform and a second latch plate attached to the frame that is engaged by the second latch arm when the ramp platform is in the fully deployed position.  
     
     
         4 . The ramp assembly of    claim 3   , wherein the second locking mechanism comprises a third latch plate attached to the frame that is engaged by the second latch arm when the ramp platform is in the fully stowed position.  
     
     
         5 . The ramp assembly of    claim 4   , wherein the single manual release mechanism comprises a handle (1) operatively associated with the first latch arm when the ramp platform is in the deployed position such that actuation of the handle causes the first and second latch arms to release the first and second latch plates, and (2) operatively associated with the first latch arm when the ramp platform is in the stowed position such that actuation of the handle causes the second latch arm to release the third latch plate.  
     
     
         6 . The ramp assembly of    claim 3   , further comprising a coupling operatively associated with the first and second latch arms so that the first and second locking mechanisms operate substantially simultaneously when actuated.  
     
     
         7 . The ramp assembly of    claim 2   , wherein the second locking mechanism comprises a second latch plate attached to the frame that is engaged by the first latch arm when the ramp platform is in the fully stowed position.  
     
     
         8 . The ramp assembly of    claim 7   , wherein the single manual release mechanism comprises a handle (1) operatively associated with the first latch arm when the ramp platform is in the deployed position such that actuation of the handle causes the first latch arm to release the first latch plate, and (2) operatively associated with the first latch arm when the ramp platform is in the stowed position such that actuation of the handle causes the first latch arm to release the second latch plate.