Abstract: A jet thruster for attachment to the outlet end of a high-liquid-pressure hose for use, among other things, in clearing drain lines or the like. The jet thruster comprises a body formed of at least hemi-spherical shape about a fore-and-aft axis that is substantially an extension of the hose. The hemi-spherical shape gives the frontal area of rearwardly and radially outwardly sloping configuration over which liquid jets stream in close proximity to that area to augment the forward thrust action against the walls of the drain line which facilitates advance of the thruster through the drain line. Ahead of the frontal area a spinner head is coaxially journalled for rotation via thrust exerted by liquid existing laterally from another jet in the spinner head. The spinner head jet(s) further create forces that are utilized for clearing the drain line of sludge, roots and the like. Further, the spinner head may carry blades or the like for increasing the clearing action of the thruster.

Abstract: A fluid pump system whose output can be varied by converting it from maximum output to a lesser output and in between by dumping or varying one of its pumping elements or pistons to the inlet side of the pump. More specifically, a pump is provided with two opposed pistons, both of which are connected to inlet and outlet for maximum capacity. The piston chamber of one piston is equipped with a converter line for leading that chamber back to the inlet, whereby only the remaining piston furnishes the pump discharge. Variations in the adjustable mode of the valve is reflected in the action of the pump relief valve to cause increased effectiveness of a jetter line supplied by the pump output.

Abstract: A relatively small, lightweight muffler is provided, especially adapted to low horsepower aircraft and comprises an elongated, essentially cylindrical structure made up of inner and outer casings having sound-absorbent-material-containing chambers and pressure-wave trap elements to minimize exhaust noises. The rear end of the muffler is in the form of a cone having its apex to the rear and containing a quantity of sound-absorbent material in a rearward part thereof and the conical wall ahead of this material being perforated. One form of the structure has a convex or hemispherical front end for aerodynamic purposes in those cases where the muffler is installed externally of the aircraft. The pressure-wave traps comprise walled structures having louvered slots therein appropriately aimed to direct the pressure waves to the sound-absorbent material.