Telescoping energy absorber for vehicle bumpers and method of assembly

Claim 2

An energy absorber unit for yieldably supporting a vehicle bumper to support structure comprising an elongated piston tube, a cylinder tube, means mounting said piston tube for telescopic movement within said cylinder tube, a floating piston mounted for axial movement in said piston tube, a cap mounted on the end of said piston tube and separating said piston tube and said cylinder tube into first and second chambers, an orifice in said cap, an oil filling each of said chambers, a helical extension spring mounted in said first chamber, means connecting one end of said extension spring to said floating piston, a metering pin extending from the end of said cylinder tube through said orifice in said cap to a terminal end in said first chamber, means connecting the other end of said extension spring to said terminal end of said metering pin, said metering pin providing means for restricting said orifice as said unit is telescopically collapsed to absorb energy imparted to said unit, said floating piston being movable in said unit in response to collapse of said unit to expand said helical spring which provides a load on the oil contained in said chambers for returning said unit to an extended position when said impact load is removed.

Claim 3

An energy absorber unit for yieldably supporting a vehicle bumper to support structure comprising an elongated cylindrical piston tube, a cylinder tube, means mounting said piston tube for telescopic movement within said cylinder tube between a collapsed position and an extended position, a disc-like floating piston mounted for axial movement in said piston tube, a cap mounted on the end of said piston tube and cooperating with said floating piston and said piston tube and said cylinder tube to provide first and second variable volume chambers, central orifice in said cap for hydraulically connecting said first and second chambers, an oil filling each of said chambers, a helical extension spring mounted in said first chamber, means connecting one end of said extension spring to said floating piston, a tapered fluid metering pin for progressively restricting said orifice as said piston tube telescopes in said cylinder tube, means securing said metering pin to the end of said cylinder tube so that said pin extends axially through said orifice in said cap to a terminal end in said first chamber, means connecting the other end of said extension spring to said terminal end of said metering pin, said floating piston being movable in said unit in reponse to the telescopic collapse of said unit and flow of oil from said second chamber to said first chamber to expand said second chamber and elongate said spring whereby a spring load is placed on the oil in said chambers to urge said tubes toward said extended position.

Claim 4

An energy absorber unit for yieldably supporting a vehicle bumper to support structure comprising an elongated cylindrical piston tube, a cylinder tube, means mounting said piston tube for telescopic movement within said cylinder tube between a collapsed position and an extended position, a disc-like floating piston mounted for axial movement in said piston tube, a cap mounted on the end of said piston tube and cooperating with said floating piston and said piston tube and said cylinder tube to provide first and second variable volume chambers, central orifice in said cap for hydraulically connecting said first and second chambers, an oil filling each of said chambers, a helical extension spring mounted in said first chamber, means connecting one end of said extension spring to said floating piston, a tapered fluid metering pin for progressively restricting said orifice as said piston tube telescopes in said cylinder tube, means securing said metering pin to the end of said cylinder tube so that said pin extends axially through said orifice in said cap to a terminal end in said first chamber, means connecting the other end of said extension spring to said terminal end of said metering pin, said floating piston being movable in said unit in reponse to the telescopic collapse of said unit and flow of oil from said second chamber to said first chamber to expand said second chamber and elongate said spring whereby a spring load is placed on the oil in said chambers to urge said tubes toward said extended position.

Claim 5

An impact energy absorber unit for mounting a bumper assembly to a support structure of an automobile 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, piston means mounted for longitudinal movement in said first cylinder, said first cylinder having a cap secured to the end portion thereof to cooperate with said piston means to form a first variable volume fluid chamber in said first cylinder and to form a second chamber in said second cylinder, a hydraulic fluid in said chambers, an aperture formed in said cap to provide hydraulic communication between said first and second chambers, an elongated metering rod extending longitudinally in said unit through said aperture to a terminal position in said first chamber, means securing said rod to one of said cylinders, a coiled spring mounted in said first chamber, means securing one end of said coiled spring to said piston, and means securing the other end of said coil spring to said rod whereby said spring will be extended in response to the telescoping movement of said first cylinder into said second cylinder and the expansion of said spring to provide a spring force on said oil in said chambers to move said cylinders to said extended position.

Claim 6

An impact energy absorber unit for mounting a bumper assembly to a support structure of an automobile 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, piston means mounted for longitudinal movement in said first cylinder, said first cylinder having a cap secured to the end portion thereof to cooperate with said piston means to form a first variable volume fluid chamber in said first cylinder and to form a second chamber in said second cylinder, a hydraulic fluid in said chambers, an aperture formed in said cap to provide hydraulic communication between said first and second chambers, an elongated metering rod extending longitudinally in said unit through said aperture to a terminal position in said first chamber, means securing said rod to one of said cylinders, a coiled spring mounted in said first chamber, means securing one end of said coiled spring to said piston, and means securing the other end of said coil spring to said rod whereby said spring will be extended in response to the telescoping movement of said first cylinder into said second cylinder and the expansion of said spring to provide a spring force on said oil in said chambers to move said cylinders to said extended position.

Claim 7

An impact energy absorber unit for mounting a bumper assembly to a support structure of an automobile 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, piston means mounted for longitudinal movement in said first cylinder, an end cap secured to the inner end of said first cylinder and cooperating with said movable piston to form a first variable volume fluid chamber and cooperating with said second cylinder to form a second variable volume fluid chamber, a hydraulic fluid filling said fluid chambers, a central opening formed in said cap to provide hydraulic communication between said first and second chambers, an elongated fluid metering rod extending longitudinally in said unit and through said central opening to a terminal position in said first chamber for progressively restricting said central opening as said first cylinder telescopes into said second cylinder, means securing said rod to said one end of said second cylinder, a coiled extension spring mounted in said first chamber, first connector means securing one end of said coiled spring to said piston and second connector means securing the other end of said coil spring to the end of said metering rod terminating in said first chamber whereby said oil is forced from said second chamber to said first chamber and said spring is extended in response to the telescoping movement of said first cylinder into said second cylinder and the extension of said spring provides a spring force on said oil in said chambers to urge said cylinders to move to said extended position.

Claim 8

An impact energy absorber unit for mounting a bumper assembly to a support structure of an automobile 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, piston means mounted for longitudinal movement in said first cylinder, an end cap secured to the inner end of said first cylinder and cooperating with said movable piston to form a first variable volume fluid chamber and cooperating with said second cylinder to form a second variable volume fluid chamber, a hydraulic fluid filling said fluid chambers, a central opening formed in said cap to provide hydraulic communication between said first and second chambers, an elongated fluid metering rod extending longitudinally in said unit and through said central opening to a terminal position in said first chamber for progressively restricting said central opening as said first cylinder telescopes into said second cylinder, means securing said rod to said one end of said second cylinder, a coiled extension spring mounted in said first chamber, first connector means securing one end of said coiled spring to said piston and second connector means securing the other end of said coil spring to the end of said metering rod terminating in said first chamber whereby said oil is forced from said second chamber to said first chamber and said spring is extended in response to the telescoping movement of said first cylinder into said second cylinder and the extension of said spring provides a spring force on said oil in said chambers to urge said cylinders to move to said extended position.