Counterbalance assembly for a fold out ramp

Abstract

A counterbalanced ramp assembly includes a ramp portion coupled for reciprocating motion between a stowed position, a deployed position, and a neutral position. First and second elements are operatively coupled to the ramp portion. When the ramp portion moves from the neutral position toward the deployed position, the first element moves a first end of a spring toward a second end of the spring as the second end of the spring maintains a fixed position. When the ramp portion moves from the neutral position toward the stowed position, the second element moves the second end of the spring toward the first end of the spring as the first end of the spring maintains a fixed position.

1 . A ramp assembly, comprising:
 (a) a ramp portion configured for reciprocating motion between a stowed position, a deployed position, and a neutral position; and   (b) a counterbalance, comprising:
 (i) a spring; 
 (ii) a first element operatively coupled to the ramp portion, the first element moving a first end of the spring toward a second end of the spring when the ramp portion moves from the neutral position toward the deployed position, the second end of the spring maintaining a fixed position relative to the neutral position of the ramp portion when the ramp portion moves from the neutral position toward the deployed position; and 
 (iii) a second element operatively coupled to the ramp portion, the second element moving the second end of the spring toward the first end of the spring when the ramp portion moves from the neutral position toward the stowed position, the first end of the spring maintaining a fixed position relative to the neutral position of the ramp portion when the ramp portion moves from the neutral position toward the stowed position. 
   
     
     
         2 . The ramp assembly of  claim 1 , wherein the spring biases the ramp portion toward the deployed position when the ramp portion is between the neutral position and the stowed position. 
     
     
         3 . The ramp assembly of  claim 2 , wherein the spring biases the ramp portion toward the stowed position when the ramp portion is between the neutral position and the deployed position. 
     
     
         4 . The ramp assembly of  claim 1 , wherein the spring biases the ramp portion toward the deployed position after the ramp portion has traveled a predetermined distance from the neutral position toward the stowed position. 
     
     
         5 . The ramp assembly of  claim 1 , wherein the spring biases the ramp portion toward the stowed position after the ramp portion has traveled a predetermined distance from the neutral position toward the deployed position. 
     
     
         6 . The ramp assembly of  claim 5 , wherein the spring biases the ramp portion toward the deployed position after the ramp portion has traveled a predetermined distance from the neutral position toward the stowed position. 
     
     
         7 . The ramp assembly of  claim 1 , wherein the spring is a pneumatic spring. 
     
     
         8 . The ramp assembly of  claim 1 , wherein the first element forms part of an endless loop. 
     
     
         9 . The ramp assembly of  claim 8 , wherein the second element forms part of the endless loop. 
     
     
         10 . A ramp assembly, comprising:
 (a) a ramp portion configured for reciprocating motion between a stowed position, a deployed position, and a neutral position; and   (b) a counterbalance, comprising:
 (i) a pneumatic spring comprising a compressible gas; 
 (ii) a first element operatively coupled to the ramp portion, the first element moving in a first direction to compress the gas when the ramp portion moves from the neutral position toward the deployed position, the compressed gas urging the ramp portion toward the stowed position when the ramp portion is between the neutral position and the deployed position; and 
 (iii) a second element operatively coupled to the ramp portion, the second element moving in a second direction opposite the first direction to compress the gas when the ramp portion moves from the neutral position toward the stowed position, the compressed gas urging the ramp portion toward the deployed position when the ramp portion is between the neutral position and the stowed position. 
   
     
     
         11 . The ramp assembly of  claim 10 , wherein the first element forms part of an endless loop. 
     
     
         12 . The ramp assembly of  claim 11 , wherein the second element forms part of the endless loop. 
     
     
         13 . A ramp assembly, comprising:
 (a) a ramp portion configured for reciprocating motion between a stowed position, a deployed position, and a neutral position; and   (b) a counterbalance, comprising:
 (i) a force transmission element operatively coupled to the ramp portion for reciprocating movement between a first direction when the ramp portion moves toward the stowed position and a second direction when the ramp portion moves toward the deployed position; and 
 (ii) a spring; 
 (iii) a first element operatively coupled to the force transmission element, the first element moving a first end of the spring toward a second end of the spring when the ramp portion moves from the neutral position toward the deployed position, the second end of the spring maintaining a fixed position relative to the neutral position of the ramp portion when the ramp portion moves from the neutral position toward the deployed position; and 
 (iv) a second element operatively coupled to the force transmission element, the second element moving the second end of the spring toward the first end of the spring when the ramp portion moves from the neutral position toward the stowed position, the first end of the spring maintaining a fixed position relative to the neutral position of the ramp portion when the ramp portion moves from the neutral position toward the stowed position. 
   
     
     
         14 . The ramp assembly of  claim 13 , wherein the spring biases the ramp portion toward the deployed position when the ramp portion is between the neutral position and the stowed position. 
     
     
         15 . The ramp assembly of  claim 14 , wherein the spring biases the ramp portion toward the stowed position when the ramp portion is between the neutral position and the deployed position. 
     
     
         16 . The ramp assembly of  claim 13 , wherein the spring biases the ramp portion toward the deployed position after the ramp portion has traveled a predetermined distance from the neutral position toward the stowed position. 
     
     
         17 . The ramp assembly of  claim 13 , wherein the spring biases the ramp portion toward the stowed position after the ramp portion has traveled a predetermined distance from the neutral position toward the deployed position. 
     
     
         18 . The ramp assembly of  claim 17 , wherein the spring biases the ramp portion toward the deployed position after the ramp portion has traveled a predetermined distance from the neutral position toward the stowed position. 
     
     
         19 . The ramp assembly of  claim 13 , wherein the force transmission element forms part of an endless loop.