Abstract: An electrical power generating apparatus is developed as an internal combustion acoustically resonant engine. It has left and right acoustic formations (39), which are formed into the apparatus closure and constitute a multiple degree of freedom vibratory system. A shuttle (12) is suspended inside and between these acoustic formations and reciprocating when two fuel injectors (35), which are positioned symmetrically at each end of said shuttle in the body of said closure, do their alternate operation and create oscillations of said shuttle. A linear generator rotor (30) is attached to said shuttle with magnetic elements producing a magnetic field when rotor reciprocates together with the shuttle. A linear generator stator with windings is attached to said closure. The fuel injectors create mechanical oscillations of the shuttle, the shuttle creates oscillations of the rotor, and magnetic field of said rotor crosses the windings of the stator for generating of an electrical energy.

Abstract: A loading gate for a mine roof bolter apparatus forms a protective canopy for mine working personnel when opened, and when closed, it seals an opening in the bolter containing manual controls and roof bolt storage cartridges. Access to the stored cartridges and controls by the personnel can only be made when the gate is open. The gate is operated by an over-center toggle joint driven by a hydraulic cylinder. As a fail-safe feature, once the gate has been fully opened, the over-center toggle joint maintains the gate open even upon failure of the hydraulic cylinder.