Abstract: A solid state laser comprises a housing having a body portion for enclosing optical components thereof. A mounting means is provided for mounting the optical components directly to the housing. The housing has stiffness sufficient for spatial and angular positioning of the optical components. A cooling means transfers heat from the optical components to the housing by circulation of a preselected gas therewithin.

Abstract: A drive mechanism for a drill provides both rotational drive and axial feed for a drill of substantial diameter such as those used to drill holes for roof bolts in mine shafts. A plurality of sprockets carry two chains of drive links which interlock around the drill shaft with each drive link having depressions which mate with scroll-like projections on the drill shaft. For axial feed, the sprockets are driven from worm drives in separate housings on each side of the chains, the worm drives being driven from gears in a gearbox which are connected through a differential gearset to a hydraulic motor. A second hydraulic motor also drives through the differential gearset to rotate the drill shaft and the entire drive chain assembly. A large diameter face seal serves as the partition between the chain drive assembly and the gearbox.