Abstract: A downhole tool includes a housing configured to be connected between two tubular members. The housing includes a chamber and a plug assembly is disposed in the chamber and divides the chamber into an up-hole portion and a downhole portion. The plug assembly includes a glass member having a predetermined residual surface compression, at least a first face, and at least one strength-reducing surface feature on the first face. The strength-reducing surface feature is configured to cause the glass member to disintegrate when the glass member is exposed to a pressure in the up-hole portion of a magnitude that creates a tensile stress on the first face that exceeds the predetermined residual surface compression.

Abstract: A bollard assembly includes a bollard post, a ground sleeve configured to receive the bollard post, and a stress control device positioned adjacent to the ground sleeve. The stress control device has a face plate and a plurality of support plates secured to a back surface of the face plate. The support plates are angularly space from one another at equal angles and extend radially inward from the back surface towards the ground sleeve such that the ground sleeve fits between the plurality of support plates.

Abstract: A bollard assembly includes a bollard post, a ground sleeve configured to receive the bollard post, and a stress control device positioned adjacent to the ground sleeve. The stress control device has a face plate and a plurality of support plates secured to a back surface of the face plate. The support plates are angularly space from one another at equal angles and extend radially inward from the back surface towards the ground sleeve such that the ground sleeve fits between the plurality of support plates.

Abstract: A safety end barrier for use in coordination with roadside barriers. The safety end barrier lies substantially parallel to the direction of traffic flow and increases in height from about natural ground level at its lower end. The end barrier has sidewalls which angle upwardly outward from the barrier base. The taller end of the end barrier is preferably connected to a concrete roadside barrier through apertures extending from a recessed trough to the end of the safety end barrier. Preferably, bolts with two threaded ends, insertable through the apertures and secured by corresponding nuts, are used as connecting devices to connect the end barrier to a concrete roadside barrier.

Abstract: A hinged gambrel support which folds and latches for storage. Each of a pair of support arms include one or more gambrel retainer projections, mating latch surfaces and tie off apertures. A bored axle at one arm mates with and is retained to the other arm at a recessed bore via a split ring fastener. Latch surfaces at the retainer projections interlock upon folding the arms for storage. In an alternative construction the arms are length adjustable.

Abstract: A low profile road barrier that minimizes obstruction to vision and the ramping and rolling of automobiles which may be comprised of one or more interconnected concrete barrier segments stationed along the road or cast in place. The road barrier usually lies substantially parallel to the direction of traffic, may be up to about 24 inches in height and has a sidewall facing toward the road which angles outwardly from the barrier base. Abutting ends of contiguous segments are interconnected by economic, easily installed and removed devices, which preferably comprise bolts with two threaded ends insertable through apertures in the segment ends secured by corresponding nuts.