Patent ID: 6997638
Filing Date: 2006-02-14
Classification: E01F

Abstract:
1. An apparatus comprising: a foundation located below a roadway surface; a housing secured to the foundation; a bollard reciprocatingly received within the housing; a plate disposed within the bollard; a spring reciprocatingly received within the bollard, and secured at a proximal end to the plate; a cylinder received at least in part within the spring; a piston shaft reciprocatingly received within the cylinder, which piston shaft is secured at a proximal end to the plate; a piston terminating a distal end of the piston shaft, which piston divides the cylinder into an upper chamber and a lower chamber; a flow line; a valve system; and circuitry connected to the valve system, which circuitry is operable to simultaneously or sequentially operate the valve system so as to selectively connect the flow line for operation on the lower chamber and the upper chamber, which operation on the upper chamber and the lower chamber causes reciprocation of the spring between compressed and extended positions, and which compression and extension of the spring causes reciprocating of the bollard between retracted and extended positions.