Device for helping a vehicle to negotiate an obstacle

Abstract

A device for helping a wheeled vehicle to negotiate an obstacle includes: a frame; a plate having two ends, a first end being movable between a high position and a low position in which the plate constitutes an access ramp; a flap constituting a front surface of the device when the plate is in the high position and provides ramp access when the plate is in the low position; and a drive assembly for driving the first end between the low position and the high position. The drive assembly includes an actuator and a carriage movable along a longitudinal axis. The device further includes a pair of side railings rigidly connected to the carriage, each having a control profile controlling the position of the plate, and a pair of resilient bars arranged between the flap and side railings.

1 . A device ( 1 ) for helping a wheeled vehicle to pass over an obstacle, the device comprising:
 a stationary frame ( 2 ) comprising a bottom ( 21 ) and two symmetrical parallel side walls ( 23 ,  24 ),   a plate ( 9 ) provided with two ends, a first end being movable between a high position and a low position in which said plate ( 9 ) constitutes an access ramp, and   a flap ( 11 ) constituting a front face of the device ( 1 ) in the high position of the plate ( 9 ) and constituting access to the ramp in the low position of the plate ( 9 ), and   a drive assembly ( 30 ) for driving said first end between the low position and the high position, said first end being supported by said drive assembly at least in the high position, said drive assembly ( 30 ) comprising:   an actuator ( 31 ) provided with a fixed end ( 32 ) supported by the frame ( 2 ) and an end movable between a retracted position and an extended position, and   a carriage ( 35 ) translationally movable along a longitudinal axis, the movable carriage ( 35 ) being translationally driven by said movable end ( 33 ) of the actuator,   a pair of side railings ( 36 ,  37 ) integral with said carriage ( 35 ) and each having a control profile controlling the position of said plate ( 9 ), and   a pair of resilient bars ( 40 ,  41 ) disposed between said flap ( 11 ) and the side railings ( 36 ,  37 ) so that in the high position, the resilient bars ( 40 ,  41 ) exert traction on the flap ( 11 ) in the closed position and in the low position, the resilient bars ( 40 ,  41 ) press against the flap ( 11 ) in the open position to constitute a rolling surface for access to the ramp.   
     
     
         2 . The device according to  claim 1 , wherein the control profile has a central portion ( 38 ) sloping so that a translation of the side railings ( 36 ,  37 ) along said longitudinal axis controls a movement of said plate ( 9 ) between the low position and the high position, and a substantially horizontal upper portion ( 39 ) so that the bearing of the plate ( 9 ) against the control profile generates a force substantially perpendicular to said longitudinal axis. 
     
     
         3 . The device according to  claim 1 , wherein the flap ( 11 ) comprises an external wall ( 13 ) in the high position, which contacts a ground surface when lowered to a low position ( 15 ) in the high position, said internal wall ( 15 ), when in the low position, provides a rolling surface, said walls being non-parallel to each other. 
     
     
         4 . The device according to  claim 1 , wherein said resilient bars ( 40 ,  41 ) comprise gas springs, and are arranged proximate to said side walls ( 23 ,  24 ) and hinged between the flap ( 11 ) and the carriage ( 35 ). 
     
     
         5 . The device according to one  claim 1 , wherein the plate ( 9 ), in the low position, rests on the frame ( 2 ). 
     
     
         6 . The device according to  claim 1 , wherein the plate ( 9 ), in the high position, rests on said side railings ( 36 ,  37 ). 
     
     
         7 . The device according to  claim 2 , wherein said upper portion ( 39 ) of the control profile desynchronizes the movement of said plate ( 9 ) with respect to movement of the flap ( 11 ). 
     
     
         8 . The device according to  claim 1 , wherein the plate ( 9 ) comprises two wheels ( 53 ) rollably mounted to the control profile. 
     
     
         9 . The device according to  claim 1 , wherein the bottom ( 21 ) of the frame ( 2 ) has a sloping portion remote from the flap ( 11 ), an electronic control board ( 22 ) being mounted to the sloping portion. 
     
     
         10 . The device according to  claim 1 , wherein the actuator ( 31 ) has an axis of translation between the retracted position and the extended position intersecting with the longitudinal axis of the carriage ( 35 ). 
     
     
         11 . The device according to  claim 1 , wherein the bottom ( 21 ) of the frame ( 2 ) has a sloping portion remote from the flap ( 11 ) and a substantially horizontal portion proximate to the flap ( 11 ), an electronic control board ( 22 ) being mounted to the sloping portion.