Abstract: A pressure regulating system having a tamper-proof safety feature. A pair of seats are mounted to an annular pipe. A first bleed pipe, with a fixed restriction, extends from an inlet conduit to a first chamber. The first chamber is separated from a second chamber by a second diaphragm. A second bleed pipe extends from the second chamber to an outlet pipe. A bleed off mechanism is sealed within the outlet conduit and includes a compressible bellows. When compressed, which occurs when a predetermined pressure level is attained in the outlet conduit, a third seat is moved out of sealing relation with the outlet conduit and the first chamber. This creates an imbalance of the pressures in the chambers that leads to the pair of seats being moved to seal off apertures in the inlet conduit, thereby inhibiting flow into the outlet conduit.

Abstract: An ergonomic demolition tool includes a jackhammer and a lift assist mechanism having a wheeled caster assembly. The lift assist mechanism has a frame which is movable between upper and lower positions to provide a lifting force to assist the jackhammer operator in raising the jackhammer.