Damped crash attenuator

A method for protecting a truck or fixed structure from damage resulting upon impact of a moving object with the truck or structure, comprising the steps of:

• mounting a movable displacement structure to the truck or structure, the displacement structure having an expanded position and a contracted position,
• arranging a bumper having an impact-receiving face adapted to receive the impact from the moving object on the displacement structure,
• expanding the displacement structure to its expanded position,
• detecting impact of the moving object with the bumper which is operative to cause the displacement structure to move from the expanded position toward the contracted position, and
• dissipating the impact energy of the moving object and reducing the velocity of the moving object by adjusting an energy dissipation force which dissipates the impact energy of the moving object such that the object is optimally brought to rest.

A crash attenuator which receives an impact force from a moving object and dissipates the impact energy of the object to thereby reduce the velocity of the object and optimally bring the object to rest, comprising

• a frame mountable to a truck or stationary structure,
• a bumper having an impact-receiving face adapted to receive the impact from the object in a crash,
• a movable displacement structure coupled to said frame and interposed between said frame and said bumper and having a first position in which said bumper is relatively distant from said frame and a second position in which said bumper is relatively proximate to said frame,
• energy dissipation means coupled to said displacement structure for dissipating the impact energy of the object received by said bumper which causes said displacement structure to be moved from the first position toward the second position and thereby reducing the velocity of the object, and
• anticipatory sensing means coupled to said energy dissipation means for sensing impending impact of the object with said bumper prior to actual impact of the object with said bumper and determining information about the object,
• said energy dissipation means being controlled to provide an energy dissipation force based on the determined information about the object.

A crash attenuator which receives an impact force from a moving object and dissipates the impact energy of the object to thereby reduce the velocity of the object and optimally bring the object to rest, comprising

• a frame mountable to a truck or stationary structure,
• a bumper having an impact-receiving face adapted to receive the impact from the object in a crash,
• a movable displacement structure coupled to said frame and interposed between said frame and said bumper and having a first position in which said bumper is relatively distant from said frame and a second position in which said bumper is relatively proximate to said frame,
• energy dissipation means coupled to said displacement structure for dissipating the impact energy of the object received by said bumper which causes said displacement structure to be moved from the first position toward the second position and thereby reducing the velocity of the object, and
• electronic control means for controlling an energy dissipation force provided by said energy dissipation means.

A crash attenuator which receives an impact force from a moving object and dissipates the impact energy of the object to thereby reduce the velocity of the object and optimally bring the object to rest, comprising

• a frame mountable to a truck or stationary structure,
• a bumper having an impact-receiving face adapted to receive the impact from the object in a crash,
• a movable displacement structure coupled to said frame and interposed between said frame and said bumper and having a first position in which said bumper is relatively distant from said frame and a second position in which said bumper is relatively proximate to said frame, and
• energy dissipation means coupled to said displacement structure for dissipating the impact energy of the object received by said bumper which causes said displacement structure to be moved from the first position toward the second position and thereby reducing the velocity of the object,
• said energy dissipation means comprise a hydraulic mechanism mounted on said displacement structure, said hydraulic mechanism comprising at least one hydraulic cylinder including a housing and a piston movable into and out of said housing, the flow of a fluid out of a space between said piston and said housing being controlled in order to vary the energy dissipation force.

A crash attenuator which receives an impact force from a moving object and dissipates the impact energy of the object to thereby reduce the velocity of the object and optimally bring the object to rest, comprising

• a frame mountable to a truck or stationary structure,
• a bumper having an impact-receiving face adapted to receive the impact from the object in a crash,
• a movable displacement structure coupled to said frame and interposed between said frame and said bumper and having a first position in which said bumper is relatively distant from said frame and a second position in which said bumper is relatively proximate to said frame,
• energy dissipation means coupled to said displacement structure for dissipating the impact energy of the object received by said bumper which causes said displacement structure to be moved from the first position toward the second position and thereby reducing the velocity of the object, and
• means for sensing motion of the object after impact with said bumper and controlling said energy dissipation means to provide a variable energy dissipation force in order to decelerate the object at a substantially constant rate.

A crash attenuator which receives an impact force from a moving object and dissipates the impact energy of the object to thereby reduce the velocity of the object and optimally bring the object to rest, comprising

• a frame mountable to a truck or stationary structure,
• a bumper having an impact-receiving face adapted to receive the impact from the object in a crash,
• a movable displacement structure coupled to said frame and interposed between said frame and said bumper and having a first position in which said bumper is relatively distant from said frame and a second position in which said bumper is relatively proximate to said frame,
• energy dissipation means coupled to said displacement structure for dissipating the impact energy of the object received by said bumper which causes said displacement structure to be moved from the first position toward the second position and thereby reducing the velocity of the object, said energy dissipation means being arranged to provide an energy dissipation force for dissipating the impact energy of the object,
• control means for controlling the energy dissipation force.