Rebound control for energy absorber unit

Claim 2

An impact energy absorbing unit for mounting a bumper assembly to automotive vehicle structure comprising first and second cylinders, support means mounting said first cylinder for telescoping movement with respect to said second cylinder between an extended position and a retracted position, said second cylinder having an inwardly extending wall portion at one end thereof, stop means fixed to said first cylinder for engaging said wall portion to establish the extended position of said cylinders, means operatively disposed in said cylinders for absorbing the energy of an impact force imparted to said bumper assembly in response to movement of said first cylinder to said retracted position, motor means disposed in said cylinders for relatively moving said first cylinder from said retracted position to said extended position in response to release of the impact force, annular resilient sleeve means mounted on said stop means and disposed between said cylinders, said sleeve means having contact means engageable with the inner wall of said second cylinder for deflecting said sleeve means inwardly in responSe to the movement of said first cylinder from said extended position and for exerting a radial drag load between said cylinders to control and reduce the return speed of said first cylinder when moving from said retracted position to said extended position, and annular housing means in one of said cylinders for permitting said sleeve means to assume an unstressed state in response to movement of said first cylinder to said extended position.

Claim 3

An impact energy absorbing unit for mounting a bumper assembly to automotive vehicle structure comprising first and second cylinders, support means mounting said first cylinder for telescoping movement with respect to said second cylinder between an extended position and a retracted position, means operatively disposed in said cylinders for absorbing the energy of an impact force imparted to said bumper assembly in response to movement of said first cylinder to said retracted position, motor means disposed in said cylinders for relatively moving said first cylinder from said retracted position to said extended position in response to release of the impact force, rebound control means operatively disposed between the walls of said cylinders, said rebound control means comprising an elastic sleeve supported on one of said cylinders and deformed by a stress exerted thereon by the wall of the other of said cylinders subsequent to the movement of said first cylinder from said extended position for exerting a radially directed friction load between said cylinders to control and reduce the return speed of said first cylinder when moving from said retracted position to said extended position, and housing means in one of said cylinders for permitting said elastic sleeve means to restore to an unstressed state in response to movement of said first cylinder to said extended position.

Claim 4

An impact energy absorbing unit for mounting a bumper assembly to automotive vehicle structure comprising first and second cylinders, support means mounting said first cylinder for telescoping movement with respect to said second cylinder between an extended position and a retracted position, means operatively disposed in said cylinders for absorbing the energy of an impact force imparted to said bumper assembly in response to movement of said first cylinder to said retracted position, motor means disposed in said cylinders for relatively moving said first cylinder from said retracted position to said extended position in response to release of the impact force, rebound control means operatively disposed between the walls of said cylinders, said rebound control means comprising an elastic sleeve supported on one of said cylinders and deformed by a stress exerted thereon by the wall of the other of said cylinders subsequent to the movement of said first cylinder from said extended position for exerting a radially directed friction load between said cylinders to control and reduce the return speed of said first cylinder when moving from said retracted position to said extended position, and housing means in one of said cylinders for permitting said elastic sleeve means to restore to an unstressed state in response to movement of said first cylinder to said extended position.

Claim 5

An energy absorbing mounting unit for a bumper assembly of an automotive vehicle comprising inner and outer cylinders, support means mounting said inner cylinder for telescoping movement with respect to said outer cylinder between an extended position and a retracted position, primary control means operatively disposed in said cylinders for absorbing the energy of an impact force imparted to said bumper assembly relatively moving said cylinders from said extended toward said retracted position, motor means operatively disposed in said cylinders for relatively moving said cylinders from said retracted position to said extended position in response to the release of the impact force from said bumper assembly, stop means secured to said inner cylinder for engaging an end portion of said outer cylinder to establish said extended position of said cylinders, annular elastic sleeve means carried by said stop means and operatively disposed between said inner and outer cylinders, said sleeve means having annular contact means extending radially outwardly therefrom, said outer cylinder having an inner wall which engages said contact means and exerts a deforming stress deflecting said sleeve means radially inwardly in response to movement of said inner cylinder from said extended position so that the force of restitution of said sleeve means will exert a frictional drag load between said cylinders to reduce the return speed of said inner cylinder when moving from said retracted position to said extended position.

Claim 6

An energy absorbing mounting unit for a bumper assembly of an automotive vehicle comprising inner and outer cylinders, support means mounting said inner cylinder for telescoping movement with respect to said outer cylinder between an extended position and a retracted position, primary control means operatively disposed in said cylinders for absorbing the energy of an impact force imparted to said bumper assembly relatively moving said cylinders from said extended toward said retracted position, motor means operatively disposed in said cylinders for relatively moving said cylinders from said retracted position to said extended position in response to the release of the impact force from said bumper assembly, stop means secured to said inner cylinder for engaging an end portion of said outer cylinder to establish said extended position of said cylinders, annular elastic sleeve means carried by said stop means and operatively disposed between said inner and outer cylinders, said sleeve means having annular contact means extending radially outwardly therefrom, said outer cylinder having an inner wall which engages said contact means and exerts a deforming stress deflecting said sleeve means radially inwardly in response to movement of said inner cylinder from said extended position so that the force of restitution of said sleeve means will exert a frictional drag load between said cylinders to reduce the return speed of said inner cylinder when moving from said retracted position to said extended position.

Claim 7

A hydraulic-pneumatic energy absorbing mounting unit for a bumper assembly of an automotive vehicle comprising inner and outer cylinders having separate contractable and expansible chambers with oil therein, support means mounting said inner cylinder for telescoping movement with respect to said outer cylinder between an extended position and a retracted position, control means operatively disposed in said cylinders for controlling the flow of oil between said chambers to absorb the energy of an impact force imparted to said bumper assembly relatively moving said cylinders from said extended position to said retracted position, motor meanS operatively disposed in said cylinders for relatively moving said cylinders from said retracted position to said extended position in response to the release of the impact force from said bumper assembly, stop sleeve means secured to said inner cylinder for contacting the end of said outer cylinder for establishing the limit of telescoping of said cylinders in said extended position, said stop sleeve means having an outwardly extending support and an annular groove therein, elastic rebound control and fluid sealing sleeve means carried by said inner cylinder disposed on said stop means and between said inner and outer cylinders to provide a movable fluid seal between said cylinders, said elastic sleeve means being seated on said support and extending over said groove having outwardly extending rib means, said outer cylinder having an inclined ramp and an adjoining inner wall which engages said rib means for exerting a deforming stress to said sleeve means to deflect a portion of said sleeve into said groove in response to movement of said inner cylinder from said extended position so that said sleeve means will exert a yielding frictional drag load between said cylinders when deformed to reduce the return speed of said inner cylinder from said retracted position to said extended position.

Claim 8

A hydraulic-pneumatic energy absorbing mounting unit for a bumper assembly of an automotive vehicle comprising inner and outer cylinders having separate contractable and expansible chambers with oil therein, support means mounting said inner cylinder for telescoping movement with respect to said outer cylinder between an extended position and a retracted position, control means operatively disposed in said cylinders for controlling the flow of oil between said chambers to absorb the energy of an impact force imparted to said bumper assembly relatively moving said cylinders from said extended position to said retracted position, motor meanS operatively disposed in said cylinders for relatively moving said cylinders from said retracted position to said extended position in response to the release of the impact force from said bumper assembly, stop sleeve means secured to said inner cylinder for contacting the end of said outer cylinder for establishing the limit of telescoping of said cylinders in said extended position, said stop sleeve means having an outwardly extending support and an annular groove therein, elastic rebound control and fluid sealing sleeve means carried by said inner cylinder disposed on said stop means and between said inner and outer cylinders to provide a movable fluid seal between said cylinders, said elastic sleeve means being seated on said support and extending over said groove having outwardly extending rib means, said outer cylinder having an inclined ramp and an adjoining inner wall which engages said rib means for exerting a deforming stress to said sleeve means to deflect a portion of said sleeve into said groove in response to movement of said inner cylinder from said extended position so that said sleeve means will exert a yielding frictional drag load between said cylinders when deformed to reduce the return speed of said inner cylinder from said retracted position to said extended position.